Micro Byte PC230

Discussion in 'Retro & Arcade' started by iMic, Jan 14, 2018.

  1. iMic

    iMic Member

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    I picked up another interesting machine earlier, a Micro Byte PC230.

    Normally I write some lengthy description of the computer including its specifications and history, but this is a new one to me. These machines were apparently both manufactured and sold in Adelaide by Micro Byte Systems. They're somewhere between an XT and AT clone, with an NEC V30 processor configurable to run at 4, 7 or 10MHz, 640KB RAM, EGA Video, a SCSI Hard Disk (WD Controller) and dual internal 3.5" floppies with a matching 5.25" external drive. The 30-Watt PSU looks to be lifted directly from an Apple II clone.

    This machine is pretty complete, with a matching monitor, keyboard, disks, books and even a carry bag for the machine itself. It doesn't boot, but the drive is detected correctly in the BIOS so I suspect it's just been erased.

    It would have been a perfect machine, except this one was built without the ISA riser fitted, so it has no card slot expansion whatsoever. Some machines were optioned with the ISA riser, and could take 2 8-bit ISA cards. It's extremely disappointing as I had hoped to install a Sound and Network card in the future. Perhaps I'll eventually find an external solution, or replicate the riser PCB, but without a schematic it's unlikely.

    However even as it is, it's none the less an interesting piece of kit, and made in SA.

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    Without the sound hardware I haven't worked out what to do with it. It does appear to be capable of running Windows 3.0 according to the factory restore disks, so I'll attempt to install that first.
     
    Last edited: Mar 4, 2018
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  2. matz

    matz Member

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    Advert from the March 1989 Issue of Australian Personal Computer

    [​IMG]
     
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  3. Flamin Joe

    Flamin Joe Member

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    Awesome stuff! Honestly the EGA monitor alone is worth the money they are getting really hard to find these days.

    Check this post over at Vintage Computer Forums. You might actually find it's not the case that the BIOS has been wiped as the BIOS is actually supplement by a softbios found on the disk. There's plenty of information on in that thread all about it so it's well worth a read.


    It's pretty cool that it looks like it came from the Education Department of South Australia judging by that folder, as both my parents were teachers in Adelaide. My dad particularly probably would of seen this system as he was teaching highschool all through the 80's and the 90's. He once brought home an Apple IIe to play around with over a weekend and later when we got a PC, the occasional software package and of course some "backup copies" of games he got from students. :D So I've definitely seen that satchel folder before or at least one like it.

    It's hard to think of it now but South Australia at the time were very much punching above it's weight when it came to computing. That satchel package was developed by the Angle Park Computing Centre which founded back in the 60's and located at the now closed Angle Park Highschool. Always makes me wonder how much an influence taking a lead in computing at early time in education played a role in creating companies like Micro Byte in Adelaide.

    Sorry going a bit off topic there as it's brought up so many memories. :D
     
    Last edited: Jan 14, 2018
  4. OP
    OP
    iMic

    iMic Member

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    Still thrilled about the EGA monitor, it's almost like new as well, no burn in and the picture is unbelievably sharp.

    I'll check the internal drive once I can write some replacement boot disks. If I boot from an MS-DOS 3.3 floppy I can access the PC230 BIOS Setup Utility, so it looks like it just doesn't have a bootable volume.

    The computer does display the same message on the screen as 3pcedev's machine over on VCFed - "IF YOU SEE THIS MESSAGE, PRESS SPACE NOW!" or something along those lines. Pressing space with the original Micro Byte boot disk in the drive starts the machine. It looks like I should backup the SOFTBIOS and PC230 utilities while the disks still work, as they could be specific to this machine and board revision.

    The Satchel package is fairly complete, even the VHS cassette is still there, although I'm not sure what's on it.

    I'm still somewhat disappointed about the missing ISA riser module, and if another Micro Byte machine comes along or if I find another one out in the wild somewhere, I may look to take some hi-res photos of the module so it can be replicated. Running the various power and data lines isn't difficult, but I would imagine the card had some kind of logic on it as well which still remains a mystery at this point.

    Otherwise I'll have to expand the machine externally through the parallel port. Something like an OPL2LPT would be nice, but the TSR driver requires a 386 or higher so its capabilities would be limited to a select few games.


    And cheers matz, pretty sweet to see a print ad from when it was new. (May even have to clean it up and have it printed to display alongside it.)
     
  5. BuuBox

    BuuBox Member

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    Looks really nice, very clean for something nearly 30 years old.

    I wouldn't be too disappointed about the lack of the ISA riser. It would have been very rare for anyone to put a soundcard in such a system - the PC speaker will be more era correct. :)
     
  6. JidaiGeki

    JidaiGeki Member

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    That is a delightful setup!

    Perhaps the chap who put up the video on Youtube could send you some closeup or clear pics of the riser? It might not be too complicated a piece of kit, seeing as the build is kind of rudimentary.
     
  7. Spearchucka

    Spearchucka Member

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  8. OP
    OP
    iMic

    iMic Member

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    Looks like mine needs the 3-chip version of the card. The other versions have the connector pins on the card, while mine has the pins on the motherboard, and the 3-chip version has a header that corresponds with that connector. Not sure if the other versions would work with some modification, depends if there's voltage differences, etc and on a machine that isn't exactly common, it would be a shame to burn up the motherboard.

    Wouldn't happen to know where to find one, by chance?

    Otherwise I could attempt to have a replica card made up, but it's not ideal. I'd have to try and build a circuit diagram from photos and get the dimensions, connector spacing, etc of the original card as well, not to mention identify and source all the matching chips and components.
     
    Last edited: Jan 14, 2018
  9. Spearchucka

    Spearchucka Member

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    they are my photos, taken today
     
  10. Spearchucka

    Spearchucka Member

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    pulled the 3 chip out. see what you mean. now i'll go digging deeper into my unopened unit to see what it has. maybe i'll fire it up as well...
     
  11. Spearchucka

    Spearchucka Member

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    Well, cracked the ol' girl open (came from Gepps Cross Girl's High) and it too has a 3 chip riser in it. Fired her up and booted from a floppy, but I may need to dig out an XT keyboard now as it doesn't seem to react to the AT one. A road I didn't particularly wish to go down. So much gear, so little time
     
  12. OP
    OP
    iMic

    iMic Member

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    Cheers for looking into it.

    I know you'd probably like to hold onto them, but if there's any chance you have an extra riser card, I'd be happy to send some cash your way for one. Actually thinking of using this machine for some things on a regular basis if I can fit a couple of extra cards in there.


    Know how that goes all too well, still have a couple of boxes of various bits and pieces to sort through, been meaning to get around to it for 4-5 weeks now.
     
    Last edited: Jan 15, 2018
  13. Nitephyre

    Nitephyre Member

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    That's pretty cool! The keyboard looks exactly like a Model M with a different badge.
     
  14. Spearchucka

    Spearchucka Member

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    Sometimes the keyboard hooked up to my PC230 will work, other times not. Sometimes it would output random characters, sometimes nothing. Tried many keyboards until I found one with an AT/XT switch. Yes! Going through 720k floppies, saving the contents with a 1.44 drive, then formatting on the PC230. Dos5 lets you name your floppy, 3.3 doesn't. Too many 0 sector errors, but I've saved a few. Another hot day in Adelaide tomorrow. More time in the air conditioned shed.
     
  15. OP
    OP
    iMic

    iMic Member

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    Still need to start imaging the system disks myself. Would normally read them on the Windows 98 PC, but it needed a replacement hard drive and I only managed to do that this evening. Still need to install the device drivers again. Then it should be ready to start reading them in.
     
  16. OP
    OP
    iMic

    iMic Member

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    Started reading the disks in. Disk 1 (SOFTBIOS, HDD Tools and INSTALL) read successfully, with the exception of one track that I suspect contained ANSI.SYS - it doesn't load correctly when booting the machine.

    Disk 2 is completely corrupt. No FAT. I'm running a sector level read on that disk now in case it can be reconstructed, but I'm not expecting a miracle. I think this second disk contained the MS-DOS 3.3 system files.

    There are some duplicate disks as well, so I'll attempt to read those and see if any contain backups of the original disks. Or any other interesting data, for that matter.
     
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  17. OP
    OP
    iMic

    iMic Member

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    Disk 2 recovery was unsuccessful. Thankfully I have Disk 1 working, and that contains the machine-specific files. I have a backup copy of DOS 3.3 customised by Micro Byte Systems as well, so it's basically a workable set.

    Worked on the machine more tonight. Discovered a couple of problems to work through, like the CR2032 battery running flat, the EGA monitor being driven at the incorrect refresh rate causing a high-pitched whine, and the SCSI drive didn't work.

    The SCSI drive came good with some gentle persuasion to unstick the head stepper. It's a MiniScribe 8425S, and it doesn't seem to be an uncommon fix - my other MiniScribe 8425 MFM needed the same procedure done to it. It can read track 0, but because the stepper doesn't move, it can detect and read the partition information, but it doesn't move beyond that. After leaving the drive to warm up and work the grease in where it needs to be, the entire drive is accessible.

    For some reason it isn't bootable though. It contains MS-DOS 3.3 and even a complete installation of Windows 3.0, along with Microsoft Works 2.0 for DOS. It just doesn't boot. I know these Micro Byte machines are a bit difficult when it comes to making a bootable drive, but I suspect it's something simple like the BIOS boot configuration, or needing the boot sector rewritten from the installation floppy.
     
  18. Spearchucka

    Spearchucka Member

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    I am in the same boat. I don't understand why my PC230 won't boot from the C drive. Maybe it was never meant to, just a relatively large storage drive. I am having a hell of a time getting a copy of disk 2 working as well. Disk 1 was formatted in the PC230 under DOS 5 then the files were read to it on a 1.44 drive under WIN ME. The PC230 read this OK but I can't replicate this with disk 2. Maybe I will set up my HC120 (another Micro Byte machine) and see if it can format and read these disks.
     
  19. OP
    OP
    iMic

    iMic Member

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    The internal drive is bootable, it does need some additional work though. Just completed it here and the machine boots from the MiniScribe.

    Ran FDISK to recreate the partition table, formatted the internal drive and ran the Micro Byte Systems INSTALL software, which copies the custom MBS boot sector, MBS SoftBIOS and MBS MS-DOS files to the internal drive.

    Then with the BIOS configuration set to "Floppy then hard drive ID 1, (reverse order)" it started up to an MS-DOS prompt.

    I'll make some repairs to this disk image (ANSI.SYS and PC230.HLP need replacement, but I have working copies of these) and upload it. Disk 2 wasn't necessary, and I'm not completely sure what it contained.
     
  20. OP
    OP
    iMic

    iMic Member

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    I've uploaded the fixed version of the Micro Byte PC230 installation disk here:

    https://app.box.com/s/e7zv0o2nv2qt7yk66386eaz3t7yacpvp


    I've created an installation guide as well, included in the archive (README.TXT) that outlines the steps I followed to make my PC230 drive bootable.

    The disk image contains the MS-DOS 3.30 operating system and utilities, the Micro Byte SoftBIOS, the PC-230 Setup Utility and the PC-230 Installation Utility - all on a single 720K disk.

    The INSTALL utility copies MS-DOS 3.30 to C:\DOS33, copies the SoftBIOS and setup utility, and writes the boot sector to make the internal hard drive bootable. It may be necessary to FDISK partition and FORMAT the drive first.

    I'd recommend using WinImage to write the disk, and make sure it's written to a known-good disk in a known-good drive as this proved problematic for a while. It sometimes helps to format the disk in the PC-230 or another 720K drive first to prepare the disk and erase any residual data on the tracks before writing.
     
    Last edited: Jan 21, 2018
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