New Toys!

[recycled]

... the VGA card thinks its hilarious to flick to black and white - most of the time.
Saving the BIOS settings or doing a CTRL+ALT+DEL sometimes gets colour mode back. Removing the DE220 and doing two power boots and it changes to colour and maintains i

VGA can use a sense pin to detect monitor type. Often, if the computer is turned on and there is no monitor connected, or the monitor is turned off unable to respond to the 'are you there', the default will be to produce a mono only display. You could have a broken wire in your VGA cable, a worn pin in the plug/socket or some other intermittent fault (dry joint blah blah :o). Sounds like you may be plugging and unplugging cards, or moving the computer while testing, possibly just enough movement to wiggle something in the chain there. Have you tried another video card?

Some BIOSes will retest the monitor with a soft-reset (ctrl+alt+delete), but mostly it will require the power to be cycled, sounds like you might be one of the lucky ones. Does it change while the system is running? That's a cool trick, time to throw away the video card.

It's been a while since I played with any digital NICs, but I remember them having banks of jumpers to change IRQ and I/O port. Might be time to get the diagnostic software out and check what cards are doing what in your box. Grab an 8bit MDA so you can be sure redirection IRQ 9 is free and see what your NIC is trying to play with. (Checkit or Syscheck should still work with MDA).

[SpidersWeb]

Cheers for that I've tried another monitor, still does it, and the problem is new.
I have another video card coming, although not sure if it works until I get it. In fairness this card has been dragged between machines a lot.

NIC is jumperless (setup program to configure) but I found out tonight it can still occasionally happen with the NIC removed anyway.

The painful thing is it's not just black and white, I can't run programs from DOS, even a DIR will give me garble.
But if it boots in colour, it's as happy as larry, and ran a full suite of CheckIt Pro checks with no faults.
I just have to power cycle until I get the Trident BIOS in colour - then I know it's good :S

Edit:
ignore the above, the disk access problems seem to have gone away, what was intermittently distracting me was that EMM386 was using the cached mono video space causing the DOS boot crash. The disk access problem was a real issue last night but apparently I've done something to fix it....

I also noticed with the RAM card removed the 386 had 2Mb of RAM, turns out whoever installed the EV-135 card originally never configured the starting address properly, I set it begin at 1024 extended, and now the machine has 5Mb of RAM, yey.

Think it's just a monitor detection issue on the card now, which is good news.

Edit2: think it's somewhat awesome that this machine has 108 working 41256-12 chips (3Mb) although 3 banks have been replaced at some stage by the looks, motherboard has 24 DRAM chips but they're weird and make up 2Mb on their own.

[recycled]

set it begin at 1024 extended, and now the machine has 5Mb of RAM, yey.

Surely that's a typo, start address 2048k? Strange setup!

think it's somewhat awesome that this machine has 108 working 41256-12 chips (3Mb) although 3 banks have been replaced at some stage by the looks, motherboard has 24 DRAM chips but they're weird and make up 2Mb on their own.

I recieved an intel above board plus 8 card, loaded with RAM from a Trade Me auction. It didn't go. Putting it in two different computers (I don't have that many vintage machines) and no luck. While sorting out memory or some other task recently, I plugged the chip part numbers on the SIMMs into yahoo and got the shock of my life. The first four were 16MB SIMMs. Putting the remaining 4 * 1MB parts into slots 1 to 4 and the card worked first time in my PS/2. 5MB total. This system usually has 3MB, 1MB on the motherboard, 4 * 256kB and a CSS 2MB EMS card in. Thinking I no longer need this, or my spare (GA-229 2M EMS) I set about testing both, and combinations of them! This was huge fun, the two EMS cards with 72 * 41256 chips each, work perfectly well together after a little dip switch jiggery pokery. So I'll see your 108 chips and raise you 36 ;o)

Disapointingly, the PS/2 model 30 only has three slots, and waiting for a 10MHz 286 to do a memory test on 4MB of bus RAM is painfully slow (bus at 8MHz, and the CSS card is loaded with 150ns chips ~6MHz). Since the EMS card was also being used as a drive shelf (model 30 designed for two drives max and I've got 2 * HDD and a floppy drive) combined with my lack of patience, I replugged the NIC and ST01 disc controller card. I'm quite happy with 3MB again.

Like your EMS card, my GA-229 has a collection of different manufacturers parts and speeds - 80, 100 and 120ns. The CSS is one make chips only, I can't believe that none of them have died yet, so that's two of us impressed by the durability of this stuff.

(sorry, bit off topic there, but I just had to share some of the tricks the vintage tech can do).

[SpidersWeb]

I'm not fussed about off toic, love to have a good yap.

Yeah it's 2048Kb, because 2Mb on the motherboard built in, then the card provides another 3Mb on top. 640K conv, 384K upper/shadow, 4096K XMS.
It seems crazy seeing over a hundred chips in rows on a home computer, PS/2 setup sounds epic.

Mine is on an 8Mhz bus as well, and the 16Mhz processor doesn't help much, especially since the BIOS likes to test the memory twice. The first 2Mb whizzes by and then doof, we hit the ISA card.
Thankfully there is a 'Press space to terminate the memory test' option tho

Switched video cards, and it always runs colour now but very occasionally I get harmless artifacts. Might need to collect a few more VGA cards
I've got Windows for Workgroups installed and it can happily mount my network partitions etc, but oh lord does it feel slow, my T5200 would eat it for breakfast.
To keep it occupied I've left the 386 busy formatting another 2Gb partition

Bunch of ISA cards arrived today, including a VESA COM/LPT/EIDE/VGA combo card, a 512K Realtek VGA (using now), ISA net card with UTP, and the usual pile of sound cards - thankfully only one modem.
Also the RAM turned up from the US that SHOULD be ideal for the T3200SX and looking at the packaging I'm 90% certain these are NOS - anywho mission for another day.

Not sure if it's been mentioned, but new toys incoming:
- Commodore 1084S CGA boxed
- Genuine IBM CGA adaptor, new old-stock, sealed in original box
- T5200/100 mainboard, 'pulled from working' = fingers crossed
- IBM PS/2 VGA
- Zip100 + disks + parallel connection

CGA gear is for the IBM PC XT, that way when I FINALLY (hurry up that man) get my 5151 back it can live with the IBM PC (and maybe share with the 286XT).

Have also setup a room with 3 desks, power points, and networking to help. Making things a lot easier!

[Carcenomy]

1084S for its CGA abilities? Sacrilege, it's capable of so much more!

[SpidersWeb]

haha yeah and having a Commodore on an IBM feels wrong too, but somewhat desperate for monitors/cards.

Happily swap for an IBM 5153

[SpidersWeb]

PS/2 VGA monitor arrived yesterday.
Have not plugged it in yet.

I'm having to stand back and flick the power switch from a distance these days when testing gear, almost 50/50 as to weither something will power up (and then can you trust it?) or just explode/smoke. That cheap P4 PSU a few weeks back gave me the biggest fright because my hand was right on the PSU at the time.

Ordered a pair of white floppy drives today. Realised I was running low (sad times).

[SpidersWeb]

Well I'll have the now working 5151 back on Friday along with it's buddy the XT286 but my new T5200 mainboard arrived
Suprisingly it came with a spare riser card which is great because the one in my machine is bent from having an old network card jammed in.
Might try the new board out later tonight if I have time.

I can't find any information on that card either, its a full length with AUI and Coax, 16bit, and "SCANET" printed on it. No brand name etc. Dated 1992 if anyone remembers it :/
Main chip is a generic 10Mbit networking chip like you'd expect to find, but was used by many card manufacturers. Only jumpers are "Adaptor Select 1,2,3,4".

Edit: did some digging, no sign of it anywhere on the internet but the chip used is the same as in the NE2000 Eagle apparently, so NE2000 clone, not much of a suprise I guess. Got that from a foreign site by adding "drivers" to my search.

[SpidersWeb]

Rebuilt the T5200 last night, finishing around 1AM :/

Before removing it, I tried repairing the old board. The only defect I could visually see was a chipset pin that'd broken free from it's solder pad. I reattached it, but still no boot.

Fitted the replacement motherboard + riser, but used my old video and RAM modules. Fired up no problems, working great, no weird quirks or crashes or anything like that. Booted up DOS and Win3.11 no worries (although it was missing its precious sound card).

Moved over the 387DX without bending any pins as well. Nice thing about the switch is that the new CPU matches the 387 - with the big white Intel 386/7DX logos

One thing I did notice, with the 80 pin memory modules removed, it had 2Mb of RAM. The modules are marked/rated as 2Mb and have it printed on them - but once both are installed there is only a total of 4Mb :/ It's always been 4Mb, I just wonder why isn't it 6Mb. I'm wondering if they're 1Mb modules labelled as 2Mb because they're 2Mb in pairs (but I could've sworn they were sold originally as 4Mb kits). On the back they each say 2M x 32 x 80. Or perhaps one is not working, or perhaps the chip RAM gets disabled? Not sure.

Edit: turns out they're 1Mb sticks, they're just labelled '2M', Max memory is 8Mb, and there is six slots, and the standard upgrade pack was 2Mb chunks.

[SpidersWeb]

Continuing on from the T5200, I've put all the screws back, fitted what looks like (but wont be) a new ESS 1868 Audiodrive, and a 3COM 3C509B - card was made in 1999 and still has no problems at all with running in an 8bit slot and being configured by software - added it to Win3.11 and it just worked. Added the machine to my Win2000 domain without any problems (I usually have SOME kind of issue). Once I sort out the floppy drive situation, this machine will actually be completely finished.

There was no need to shorten any expansion cards - the rebuild/replacements seem to have corrected any misalignments.

Flatmate is picking up my 5151 and 286XT this morning. The replacement 5150 board I got did not boot either, so I will be using the LanSoft ROM in a 2364 adaptor to try and determine if the issue is RAM ROM or other. My guess is the first 64KB of RAM, but will see.

Old ROMs arrived last night but they've all (but one) had the stickers removed and are either completely erased or half the data is missing. I was somewhat hoping to post up the binaries of what I found, but nevermind. Half are 2732 and 2716 which I'll be posting to someone else shortly (anything smaller than 8KB isn't really any use to me). The other half were a couple of 64's, a 128, and mostly 256 chips.

[SpidersWeb]

OH C'MON

286XT was working fine, put two MFM drives in it, was booting up no worries, put case back on, all good.
Left it on for a few hours, then powered it off. Few hours later power it back on and now all it does is display '007' and stops.

So now, of my 4 XT/AT machines, the only one that works is the one that arrived with a DEAD sticker on the front.
All with different issues. I'm being careful, using a static strap etc, blargh.

[SpidersWeb]

just read the ROM
Unless it's normal for the first 1800 bytes of a ROM to be "FF" I'm assuming it's forgotton a few things.

Also this morning instead of 007 I just had a cursor.
Naturally, I have no chance of finding the original BIOS again, so am going to have to plug in some others and see what happens :/

Edit: not so sure now, I'm wondering if 1800 is the offset, because the HI chip starts in the same place.
Edit 2: yeah definately a match, HI/LO thing is kind of painful to try and read ASCII with.

[tezza]

OH C'MON

286XT was working fine, put two MFM drives in it, was booting up no worries, put case back on, all good.
Left it on for a few hours, then powered it off. Few hours later power it back on and now all it does is display '007' and stops.

So now, of my 4 XT/AT machines, the only one that works is the one that arrived with a DEAD sticker on the front.
All with different issues. I'm being careful, using a static strap etc, blargh.

Sound like your toys are keeping you busy.

It can be hard to juggle several hardware projects at the same time. I've got limited space (both in my workshop and in my head ) so I tend to just focus on one machine at a time until it is either fixed and configured it completely, or I give up and put it in too-hard pile where it remains until I have nothing else to do. Then I might drag it out again for another crack.

[SpidersWeb]

Yeah I'm going to need to do the same I think. Too much fail.
XT will be my priority. 286XT and 5150 will have to wait.

Not looking forward to desoldering the XT, so many caps on that line measuring 0 :/

[SpidersWeb]

On the bright side, fixed one of my 360KB drives with ImageDisk (has an alignment tool) and a Phillips.

Read an existing disk created by my 1.2 drive.
Also formatted a system disk and booted off it.