Posts Tagged ‘Hardware


Motherboard: Aopen AX34-U

I’ve been rather busy of late, and it’s been raining here in buckets, so finding the time for photographing a board has been tricky. In any case I had some time today and have found a socket 370 board made by Aopen.

I wasn’t able to decipher the date of manufacture from any of the date codes on the board, but it’s almost certainly made around the early 2000’s. It supports the Tualatin and Coppermine cores of the Pentiun III and Celeron chips. The Coppermine ones had a reputation of being quite good at over-clocking at the time.

Looking at the board as a whole the layout is pretty standard for the time, although I’m puzzled as to why the AMR slot is right next to the AGP slot. I’ve never seen an AMR card in the wild, probably because they were pretty poor software modems. On this board it occupies what would be a prime spot for a PCI slot, which I’d much rather have.

You’ll also note it still has a legacy ISA slot, something which disappeared from consumer hardware in a few short years around the time this board was made. ISA slots stuck around for a surprisingly long time, partly due to the amount of hardware that was made for it. It was used for many unusual cards some for controlling industrial machines. I have one somewhere that was used as a lighting controller for dance floor lighting in a pub. Machines made for industrial conditions kept the ISA slot for much longer.

Unfortunately this board seems to have suffered leaky caps, a common cause of failure for many electronics. One has coated a surrounding chip with it’s goo. This kind of problem can be repaired, but it isn’t usually done because of the time or cost involved if you pay someone to do it. If you have the time, patience and skill you can clean up the goo and replace the caps, often restoring the device to functionality. I’m not confident I can repair this yet, as my soldering skills are pretty much hobbyist level. It’s easy to damage a board like this as it has very fine traces and small pads designed for machine assembly.

Performance wise this would have been quite a nice piece of kit. It has a VIA Apollo Pro 133T chipset which was a reasonable performer as well as being cheaper than alternatives. It had room for 1.5Gb of RAM providing you used the expensive-at-the-time 512Mb modules. With only 3 SDRAM slots you couldn’t use many of the cheaper sticks to make up the difference, but few people were going for more than 0.5Gb of RAM at the time.

From a technicians point of view it’s fine in terms of specs, but the board silk-screen isn’t as helpful as others when connecting the front panel and setting jumpers. The front panel is marked, but isn’t real easy to read, which can be worse in the tight confines of a case. Luckily there aren’t too many jumpers as software controls much of the settings, most of the jumpers you won’t need to touch with perhaps the exception of the one that sets the FSB speed. The manual is also still available if you need further help.

As an end user this would have been quite a good buy, it has most things you need integrated (except NIC) and has a decent chipset with support for a decent range of configurations. You could build either a cheap and cheerful machine, or something with pretty good performance with a board like this one.



Campbell Scientific C20 Cassette interface

Today we’ve got something unusual, a RS-232 Cassette interface made by Campbell Scientific. They seem to have always been specialised in making data logger and acquisition system. I can’t be sure, but I think this device was used for storing digital data on audio cassette, a common media of the time. Micro computers of the time did this as well, but usually had this function built in. It’s likely that this would have been used with machines that didn’t have that capability natively, like a PC or perhaps some scientific equipment that can speak RS-232.

It’s built in a very sturdy and quite large metal enclosure. It feels very well made, the few switches on it (including the small DIP switches) feel like quality components that have held up quite well.

The enclosure probably could have been smaller, but here you can see it probably wasn’t specific to this one device. The card cage only houses two cards here, but could have had 5 which would have been enough room for something more complicated.

Here is the processor board, it has a Z80 CPU which would be running at 4Mhz. Around it are mostly simple logic chips in the 74 series, but directly bellow the CPU are two 2k word x 8bit SRAM chips as well as the EPROM. Interestingly the SRAM chips (CDM6116AE3) were used in the memory expansion socket on the MPF-1, I may be able to use one of these to expand my unit. Handily every chip is socketed, so repair (or salvage) is significantly easier. The board appears to have been designed by hand, as you can see many of the traces are quite curvy, it’s clear a great deal of care went into its design.

The front panel board has very similar construction, everything in sockets and hand designed PCB. All the input and output circuitry is on this board and includes a Z80 serial IO chip and two CTC (counter timer circuit) chips. Given that this is a tape interface there is a distinct lack of DAC or ADC chips, most of the smaller chips are 74 series logic, a couple of opamps and serial line drivers and receivers. I suppose other machines (like the ZX spectrum) didn’t have those chips for storing digital information on tape, so they probably use a similar technique. It does make it clear that analogue or audio data is not supported by this device.

I’m a bit conflicted about what I’ll do with this particular device, the collector in me says keep it, but I don’t have a lot of space or use for it. I may end up just keeping the boards for parts, as they are all fairly usable chips with data sheets available.



Motherboard: ASUS P4S800 MX SE

Today is another of my more modern mother boards, the ASUS P4S800. It was made late 2003, roughly half way through the life of the Pentium 4, which was starting to look old compared to the new AMD Athlon 64 processors that were released that year. This board is clearly designed for the cost conscious but still has an impressive feature set. Here’s an overview of the board.

My particular example has had a custom heat sink clip fitted, likely for a custom heat sink made for increased heat dissipation. That’s a little strange as it was later P4 processors that were known for using lots of energy and running hot. Unfortunately the clip is broken, but could be replaced with an original clip to get the board working.

CPU support includes 800Mhz FSB processors such as the Northwood, Williamette and Prescott cores. If you had a newer operating system such as Windows XP or Linux you could also take advantage of Hyper threading which essentially takes unused resources in a core and makes them available for use as a secondary logical core. To the casual user it looks like you get two cores for the price of one, however, if the primary core needs more of the processing resources the second one can get slowed down significantly as it gets starved of resources. It could also cause problems with the cache as both logical processors shared it and it consumed more power adding to the heat problems.

There is support for DDR400 which is as fast as that memory standard went. It does not support running the memory in a dual channel configuration, likely because there is only a single memory channel. Having only two memory slots is probably the most limiting part of this board as it would have meant a practical maximum of 1GB of for most users.

The chip set was made by SiS, which was known for making more of the budget parts. By this stage they had managed to sort out the driver and software problems that plagued earlier chip sets, so you can expect reliability from a board like this one. The chip set integrated graphics would have been ok for basic desktop use, but completely inadequate for much else. Luckily there is an AGP slot for adding your own GPU.

The P4S800 has quite a few integrated peripherals such as USB 2.0, SATA, LAN and audio. For a small form factor board this was basically necessary as there is little room for expansion slots in many mATX chassis which sometimes also require low profile expansion cards. It also has quite a number of useful legacy ports such as RS-232, parallel, and joystick ports (with a header).

img_2536Looking closely at the CPU voltage regulation there are a number of parts not populated on the board. The missing parts are filter capacitors and power transitors/MOSFETs. It’s not really a problem unless your processor requires lots of power. I wouldn’t put a Prescott core P4 processor in this board for this reason, as they have a much higher power demand.  It might work (or not), but would almost certainly shorten the life of the board.

Working on this board is fairly easy, almost all the jumpers are labeled quite well, and the front panel section is colour coded as well. Auto detection and software configuration (in the BIOS) take care of most configuration like modern motherboards. The only reason you would need the manual is to check the compatibility lists within for memory and CPU. Most of the integrated components are either integrated into the chip set or are Realtek devices, both of which are easy to get drivers for.

For the end user this board is very similar to the Aopen P4 board I’ve looked at before, only a little newer and faster. It probably wouldn’t suite someone looking for high performance, and may be have limited expandability depending on the chassis it is installed in. For general office/internet use it would probably have done the job, and would have been reasonably reliable providing the power regulator isn’t overly stressed.


The Remains of an Epson and Reply Corp PC.

Whilst I was on holiday at my parents place I did some photography of old hardware I  have. I got out the remains of two currently dead PCs, one an Epson PC AX2 and another, a Reply Corp machine.

The first machine was made by a company called Reply Corporation (or Reply Corp for short). Interestingly there is absolutely no information available about the company online, almost as if they had never existed. I did manage to find a few machine reviews within the Google books archive of some PC magazines, but other than that nothing really. There was a segment or two featuring them in the Computer Chronicles (an old American TV Show) but I couldn’t find the particular episode.

As far as I could tell Reply Corp started out making PC cards for Macintosh machines. These cards brought PC compatibility in a limited degree to Apple machines so that popular software like Lotus 1-2-3 could be used. It seems that somewhere along the line they started making their own clone machines. They were one of the few third party manufacturers to actually purchase the rights and make MCA (mirco-channel architecture) machines. With MCA failing in the market and PC cards being a very niche product, it’s no surprise that Reply Corp disappeared into obscurity.

The machine I have is one of the MCA machines, a model 16 with a 486dx 33Mhz chip, note I’ve stripped out the drives and power supply for use else where. Unlike the IBM MCA machines it doesn’t use a fancy modular and tool-less design, instead opting for more standard mounts for the drives and power supply. This made it easier to replace these components without having to buy proprietary ones like those in the relevant IBM machines. Note the CPU is mounted on a module, we’ll take a closer look.

Here’s the CPU module up close. At the time PCs generally had either the CPU soldered onto the board, a standard chip socket (DIP/PLCC for the 286) or an old style LIF (low insertion force) for the 386 and earlier 486 machines. These solutions made upgrading a CPU a difficult task, if not impossible. Reply addressed this by using an easily replaced module, something quite unique amongst IBM PC compatibles of the time. This particular module has a 486dx chip rated for 33Mhz, but when it was running the BIOS reported it as a 486SX @ 25 Mhz, so I wonder if this is the original chip. The oscillator on the board is 50Mhz, which would indicate the module was made to run at 25Mhz (the oscillator frequency is usually halved).

The motherboard has a Chips and Technologies chip set along with a relatively thick layer of dust. It has on-board VGA graphics and unusually 2 25-pin serial ports and 2 parallel ports. Chips was never known for high performance, but they are usually quite compatible. They may have been one of the few to make a third party MCA chipset.

We got the machine originally as a replacement for our aging 386sx, it served us well for playing MS-DOS games for quite a few years. I believe it may have been ex-government as it had a SCSI hard disk and controller as well as a token ring network card. It has an unfortunate annoyance of requiring a setup boot disk to configure the BIOS settings much like IBM machines did. Unfortunately there doesn’t appear any way to get a disk now. The board has since failed, giving a BIOS beep code indicating a parity error. I’ve tried resuscitating it to no avail.

The second machine is an Epson PC AX2, which is essentially a pretty bog standard clone 286 running at 12 Mhz. My uncle gave it to my Dad for some reason, and it was basically dead upon arrival as it was already missing its power supply.

The insides of this machine are looking bare among our reading material on the table. I had stripped out the I/O cards it had some time ago. It had a MFM hard disk controller, an EGA card and a floppy controller. It doesn’t have much integration on the board despite the number of chips, basically only a keyboard port is provided.

It has a AMD made 286 running at 12Mhz. You may notice it has the Intel copyright on it, this is because AMD was a second source manufacturer of the 286 (and other earlier processors) to ensure availability of the parts. This would be the last processor that AMD would second source for Intel, as they stopped co-operating before the release of the 386.

This machine has a module as well, even mounted and connected in a similar fashion. The difference is this module appears to be for the main memory and ROM for the machine. It’s an odd design choice, but perhaps the ROM and memory design were shared across models and designs of Epson machines. This would not be an upgradable module, memory upgrades often came in expansion cards for the ISA bus.

These three chips seem to confirm what I had seen online, that this model was originally released sometime in 1986. What’s interesting is the date code for these chips indicates the 23rd week of 1989, which would have made this machine quite obsolete at the time of manufacture. I’m surprised they didn’t upgrade the design to 16 or 20Mhz as they were common speeds for the 286. The three chips are almost certainly the base mother board components such as interrupt, timer and DMA controllers.

IMG_2530Here is the reason I can’t run this machine currently. It has a power connector with an unknown pin-out, and with the original power supply missing I don’t have much chance unless there is some documentation around. This is unfortunately common for earlier PCs as standards hadn’t been formed yet.

I’ve been keeping both these old machines in the hope that one day I might find or work out the information needed to get them to work again. They’ve unfortunately languished under a table in my room at my parents place collecting dust, I hope they’ve at least been somewhat interesting to look at today, as they aren’t much use as they are.


Storage room finds – part 2

A few weeks ago I salvaged some equipment from a room clean-out, see the first post to see all the ISA bus parts and loose chips. Today we’ll be looking at the PCI cards, which are unsurprisingly all Adaptec parts. They are different from the older parts from last time in a few ways, firstly their construction is radically different because they use mostly surface mount components. They have fewer component counts with much much more integration on ASIC chips instead of off-the-shelf parts. Finally, Adaptec typically made some of the better SCSI cards with more processing done on the card rather than the host machine, this meant more CPU for applications and higher data through-put.

The first card here is an AHA-3940uw. This card was available for UltraSPARC systems as well as PCs. It doesn’t have RAID capabilities, but will do DMA transfers with-out CPU intervention to save processing on the host.  It requires the host system meet PCI specification 2.1 and that PCI-to-PCI bridges work on the host chip-set. I believe that this is because the middle chip is such a bridge and the chips on each side manage one channel each. The bridge chip appears to be manufactured by DEC (Digital Equipment Corporation also known as Digital for short) which is interesting as they weren’t really in the expansion card market.

This card appears to be from the late 90’s, it even still has MS-DOS support even though that wasn’t relevant at the time.

Here we have an ASC-29160 a 64bit PCI-X card from around 2000. PCI-X allowed for faster transfers to and from the card, which could have made quite a difference. Cards such as these could have something like 15-30 devices connected at maximum, although many fewer in practice (due to physical limitations of having that many HDDs). Many hard drives could easily generate more data than the standard PCI bus could handle (133MB/s) thus making the bus a bottle neck in the data flow.

The PCI-X standard can achieve twice the speed of PCI if running at the standard 33Mhz, but can get much faster with higher clock speeds that were offered. The most common speeds you’ll find are 33Mhz, 66Mhz and 133Mhz, but higher speeds were developed although not widely used.

This is a AHA-3940AUW which is essentially a redesign of the first card. It offers the same number of ports (at the same speed) plus a legacy SCSI connector all from the one integrated chip. It seems from the date codes that it was manufactured about a year later, so it’s probably just an incremental improvement (perhaps just for cost).

Adaptec also made lower end cards, here’s an example of one, an AVA-2906. It was made roughly mid 1999, but only supports the older SCSI standards at much lower speeds (10MB/s). It could have been used in the consumer market for scanners and early CD burners, both devices with lower bandwidth requirements. Whilst not being any faster than the ISA cards from last time, it would most certainly have cost significantly less.

Lastly here is a AHA 2940UW, which is basically just a scaled down version of the 3940 cards shown earlier. Whilst it’s not remarkable, it is a handy card as it supports most of the SCSI standards without being complicated or expensive.

That’s all the PCI SCSI cards that were saved, I did note a few things about them collectively as a group. Firstly most of these cards appear to be similar in both age and features, and they are all Adaptec cards. This was a common practice for a few reasons,  mostly ease of replacement (and fewer spares required) and less hassle when commissioning new equipment. It can save lots of time.

I’ve used Adaptec cards frequently specifically for their RAID feature, none of the cards here have this feature. The original machines mustn’t have needed either the additional space, speed or redundancy that RAID affords, as most of the cards featured also came in a version that supported RAID, but would have been more expensive.


Storage room clean-up

Recently at work we’ve had a little clean out of a storage space that had some old and unused computer parts among other items no longer being used. It turns out some quite interesting and useful old parts were in storage there, some of which I’ve been allowed to keep. This is of course on the condition that any data on any device or media is securely erased.

Most of the computer parts are Adaptec SCSI cards of various vintage, but there are also a few other ISA cards, loose chips, a couple of hard drives, and an amount of tape media that will be useful for some of my tape drives. So too much to show in one post, this time I’ll be looking at the loose chips and ISA cards.

First up we have these spare chips. The four at the top are SRAM chips, although it has been difficult to determine the exact size and pin-out, I think they are 256 x 4bits. The data sheet is proving elusive for these. The bottom three chips are EPROMs, the two left most being hitachi HN462732P chips and the right a NEC chip. The middle chip of the three is a OTP (one time programmable) so is basically of no use unless it is blank, but the other two are UV erasable so may prove useful in the future for repairs.

Here is what appears to be an early SCSI card made by Trantor in 1992. There seems to be little information about Trantor around on the internet, but it seems they were bought out by Adaptec at some point, although this doesn’t seem to be documented. If I remember correctly they were known for the tape drives they made.

This particular card is handy as it will fit an XT class machine and appears to have the chips and ROM necessary for booting of the SCSI disk. There are even still some MS-DOS drivers available for it. The silk screen has the jumper configurations, so I shouldn’t need a manual to use it.

Here we have two IO cards, one with an Acer chip-set and the other with one from UMC. These cards would have been exceptionally useful for 286 and 386 machines as they have most of the IO you would need all on one card. They both have two serial ports, a parallel port, a joystick port, floppy drive connector and a hard disk (ATA) connector. Quite the array of ports indeed for one card! The main problem with having one of these today is finding out what the jumper settings on the board are, there isn’t any silk screen to speak of.

This is an Adaptec AHA-1542b, made in early 1993 from the date code on the main chip. It supports SCSI-2 and can transfer data at about 10Mb/s connecting up to 7 devices. It’s interesting because it has a floppy connecter as well as the usual SCSI connection. You may notice that it has two ROM chips, one is the usual BIOS extension to allow for operating systems like DOS to access the disks. The other is micro-code for the boards controller.

Finally here we have two cards, both Adaptec. One is an AHA-1510A and the other is an AHA-1522A. You may notice that both actually use the same board, just the 1510A has far less components populated. The 1510A is basically a stripped down card with all the extra bells and whistles removed to make it cheaper. The user manual for it says that this cheaper card is “utilizing the CPU’s untapped power to improve system I/O performance.” So I’d say that it doesn’t have DMA support on the cheaper card among other missing features.

I had a look on the Adaptec website for all the cards shown today, and surprisingly despite their age downloads and manuals still exist. I can only applaud them for still offering the downloads, I only wish more manufacturers did the same.

Next time I’ll show the various PCI and PCI-X cards, and yes they are all Adaptec.


Motherboard: MS-6153VA

Today I’m looking at a Socket 370 board that would have been made roughly in 1999-2000. It was an interesting period as much of the early legacy technology such as the ISA bus was fading out, marking the beginning of the end for complete backwards compatibility. It is also close to the end of configuring major component with jumpers, replaced with auto-detection and software control. Although this particular board still has a few jumpers.

It’s a MS-6153VA made by MSI, a manufacturer known for making  boards with gaming and over-clocking in mind. It seems they were one of the first to offer over-clocking as a feature quite early in the history of PCs. Surprisingly it was a 286 mainboard, a time when overclocking meant replacing the crystal oscillator. They still cater to the over clocking market with a series of boards dedicated to it.

Here’s an overview of my board.


It’s remarkable because there are actually two boards with the same model number that differ significantly. This board has a VIA chip-set and is marked MS-6153, but if you search for that online you turn up a board that looks almost identical but has an Intel chip-set instead. The model number used in online references is MS-6153VA for the VIA chip-set. This must have caused some confusion at the time.

IMG_2492Here’s something different, 4 LEDs to indicate the current status of the system. If there was a problem they could use these instead (or in addition to) the standard BIOS beep codes. It wasn’t something you’d find commonly, but was extremely useful if you were lucky enough to have a visual indication. Some manufacturers took it further, using two 7 segment displays instead.

IMG_2493Like a previous Socket 7 board, this has a thermister mounted in the middle of the CPU socket. They’ve used a different package, a small flex with the component built in. I’m guessing they did this in an attempt to get a better reading closer to the CPU.

The chip-set is a VIA Apollo Pro 133A, which would have been quite decent for the time. Around the main chips are some of the reference silk-screen, which are quite handy, but are unfortunately quite distant from the jumpers they are a reference for! This may have been necessary due to the layout of the board, and I’m sure the manual would tell you where to find them, but it is annoying as it seems to effect every single silk-screen reference.

Speaking of the manual, I was able to find a download on the MSI website, however it was in the form of a EXE file! Since I’m using my Mac book I wasn’t able to easily open it, bad form MSI.

IMG_2497Next to the floppy connector is a connector that seldom got use in desktop machines. It’s an infrared header! Wireless technology had yet to really evolve into what it is today, and a cheap and simple technology commonly used was infrared, still used today in TV remote controls. It wasn’t commonly used mostly because IR (as it’s commonly called) relies on direct line of sight, and can easily be interrupted. These IR devices were usually treated as a serial port, so software like hyperterm was usable with them. In use they usually proved to be slower and less reliable than just using a cable.

From a technicians view-point it’s also fairly decent, it supported Intel and Cyrix chips up to 800Mhz which was decent for the time. It could also support the large 256Mb SDRAM sticks running at 133Mhz, allowing for a maximum of 768MB of RAM. There are also some rudimentary overclocking features on the board. The main annoyance is with the silk screen reference being so distant from the jumpers, and not having very descriptive names. Still, you could set this up without the manual.

Feature wise this board would have satisfied most end users, although audio and ethernet isn’t integrated. At that point in time integration hadn’t become the norm for those. Luckily there are plenty of PCI and ISA slots so it wouldn’t have been much of an issue. With the right CPU, RAM and GPU it probably would have even made a decent gaming rig for the time.

Blogs I Follow

Enter your email address to follow this blog and receive notifications of new posts by email.

Mister G Kids

A daily comic about real stuff little kids say in school. By Matt Gajdoš

Random Battles: my life long level grind

completing every RPG, ever.

Gough's Tech Zone

Reversing the mindless enslavement of humans by technology.

Retrocosm's Vintage Computing, Tech & Scale RC Blog

Random mutterings on retro computing, old technology, some new, plus radio controlled scale modelling.


retro computing and gaming plus a little more

Retrocomputing with 90's SPARC

21st-Century computing, the hard way


MS-DOS game reviews, retro ramblings and more...