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IBM 5150 resurrection

JDT said:
Sorry for the super multi-posting. But I changed the RAM setting to 16K, as per the switch settings in the .jpg image listed above and it booted in to BASIC.. sweet... ...now to find out why it doesnt like that RAM, might I need to remove and clean all the chips?
Click to expand...

It would be 64kB on your 5150 as it has the second revision motherboard :)

At least bank 1 is good - this memory is soldered to the board and can be a pain to replace! The other 3 banks are socketed.

What you can do now is to then change the switches to add bank 2 (total 128kB) and test, then bank 3 (192kB) and test and finally bank 4 (256kb), and test.

You should be able to work out which bank is faulty. Take out the chips in the faulty bank, clean them, and replace. If it is still broken then substitute the faulty bank with a row of chips from your SixPakPlus card. You should end up with a full 256kB working on the mainboard.
 
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dongfeng said:
It would be 64kB on your 5150 as it has the second revision motherboard :)

At least bank 1 is good - this memory is soldered to the board and can be a pain to replace! The other 3 banks are socketed.
Click to expand...

When I have it set to use bank 0 @ 64K, IBM basic reports about 12K worth of available memory.


dongfeng said:
What you can do now is to then change the switches to add bank 2 (total 128kB) and test, then bank 3 (192kB) and test and finally bank 4 (256kb), and test.
Click to expand...

Bank 1 apears to have issues, I'v tried swapping ram chips from the other banks over in to bank 1, no change when I set it to use Bank 0 & 1 @ 128K


I'm going to give my motherboard a bath in hopes of resolving... or shall we say DISolving the issue ;) cmon.. that was funny...
 
I boo-booed. A 5150 memory error has the 201 bit last.

Information derived from the first edition of 'Upgrading and Repairing PC's (Scott Mueller)':

5150's give a 4 digit code before the 201.
The first two digits are the two most significant digits in the failing address, e.g. "10" means a failing address in the range 10000 to 10FFF (64K to 68K)
The next two digits indicate the failing bits, e.g. 51 (01010001) means that bits 6, 4 and 0 failed.


ADDRESS TO BANK MAPPING FOR 16/64K 5150 MOTHERBOARD

00xxx to 03xxx = Bank 0
04xxx to 07xxx = Bank 1
08xxx to 0Bxxx = Bank 2
0Cxxx to 0Fxxx = Bank 3


ADDRESS TO BANK MAPPING FOR 64/256K 5150 MOTHERBOARD

00xxx to 0Fxxx = Bank 0
10xxx to 1Fxxx = Bank 1
20xxx to 2Fxxx = Bank 2
30xxx to 3Fxxx = Bank 3


And so with your 64/256K board, bit 2 in bank 3 is the problem.
That corresponds to chip U88.
 
BTW. "Parity Check 1" indicates that there's a RAM error on the motherboard. "Parity Check 2" indicates that there's a RAM error on an I/O card. For the POST to know what RAM was where, the motherboard switches would need to be correctly set.
 
OK, so given that my board is the 64-256K model, with all 4 banks populated.
Sw1 set to 10001111 <-(xx00xxxx to use all 4 banks) and Sw2 set to 10011000. <-(256K)

I gave the motherboard a bath last night (hot water and a toothbrush).
and am now getting '3008 201'

Here is my RAM..

http://www.jdthiele.com/personal/5150g.jpg

which dang chip is it?! I'm finding multiple interpretations of the error code, below is the most specific I could find, not sure if its correct..

------------snippet---http://www.student.nada.kth.se/~d94-tan/pckort/ps2code.txt---------------

201 Memory test failed
The ERROR shows the bank number in the leading characters
5150/4450 (PC-1) Failing Memory Module Bit/Bank Location: 16-64K planar
Code: xyzz 201 if x=0, then the failing memory is on the planar
for x=0, y=0 -> Bank 0 (row closest to the expansion card slots)
for x=0, y=4 -> Bank 1 (2nd row from the expansion card slots)
for x=0, y=8 -> Bank 2 (3rd row from the expansion card slots)
for x=0, y=C -> Bank 3 (row closest to the speaker connector)

zz=00 -> Parity Bit - chip on the left side of planar (keyboard
connector is on top)
zz=01 -> Bit 0 - chip to right of Parity Bit
zz=02 -> Bit 1 - chip to right of Bit 0
zz=04 -> Bit 2 - chip to right of Bit 1
zz=08 -> Bit 3 - chip to right of Bit 2
zz=10 -> Bit 4 - chip to right of Bit 3
zz=20 -> Bit 5 - chip to right of Bit 4
zz=40 -> Bit 6 - chip to right of Bit 5
zz=80 -> Bit 7 - chip to right of Bit 6

(PC-2) Failing Memory Module Bit/Bank Location: 64-256K planar
Code: xyzz 201 if x=0-3, then the failing memory is on the planar
for x=0-3, y=0 -> Bank 0 (row closest to the expansion card slots)
for x=0-3, y=1 -> Bank 1 (2nd row from the expansion card slots)
for x=0-3, y=2 -> Bank 2 (3rd row from the expansion card slots)
for x=0-3, y=3 -> Bank 3 (row closest to the speaker connector)

The zz codes are exactly the same as the PC-1 mapping

5160/5155/XT370/5531/4455 Failing Memory Module Bit/Bank Location:
(64-256K planars OR 256-640K planars)
Code: xbbbb zz 201 if x=0-3, then the failing memory is on the planar

The zz codes are exactly the same as the PC-1 mapping

------------/snippet----------------------
 
Well, the explanation for the 16-64K board matches mine, but the 'failing bank' portion for the 64-256K board is different.
Anyway, you are now seeing '3008 201'. According to my explanation, that's a failure of bit 3 in bank 3. That corresponds to chip U89.

Code: 
U85   U86 U87 U88 U98 U90 U91 U92 U93
------------------------------------
 P     0   1   2   3   4   5   6   7
I opened up my 5150 with the 256K board. Removed U89 and saw a '3008 201' error.
 
Perhaps a dumb question, but the first RAM chip in the bank is a 'parity' bit. Is there something special about the specific chip in these sockets? they apear to be the same as the rest of the RAM chips. What makes it a 'parity' bit?
 
2055-201 error

2055-201 error

The error means that the DIP switches are set incorrectly.
 
sweet, by swapping chips after FINALLY understanding the location codes... I can set it to use all 256K on board. I had to take a row of chips from my 6packplus card to do it.. where can one buy those little chips? I'll have to check ebay. Course.. my sixpackplus card looks a bit worse for wear.. maybe I should try to find a new one.
 
JDT said:
Perhaps a dumb question, but the first RAM chip in the bank is a 'parity' bit. Is there something special about the specific chip in these sockets? they apear to be the same as the rest of the RAM chips. What makes it a 'parity' bit?
Click to expand...

On these systems it is the same chip as others in the bank. But the chip keeps track of the parity for that bank that the memory controller uses to detect if a parity error has occured. It is important to note that some parity errors can happen without this mechanism detecting them.
 
JDT said:
sweet, by swapping chips after FINALLY understanding the location codes... I can set it to use all 256K on board. I had to take a row of chips from my 6packplus card to do it.. where can one buy those little chips? I'll have to check ebay. Course.. my sixpackplus card looks a bit worse for wear.. maybe I should try to find a new one.
Click to expand...

Just shuffle the empty row to the last row on the expansion card. At least you will be able to get 576kB of total memory (assuming the rest of the chips are ok!). You will have to change the switches on the card to change the amount of installed memory. Settings are below:

http://www.thegreenhouse.us/th99/i/A-B/50651.php

Chances are, the SixPakPlus card is absolutely fine ;) I would expect it needs a new battery by now, but that is a simple fix. The RTC is a very useful addition, Modem7 has the drivers on his web page.
 
dongfeng said:
Just shuffle the empty row to the last row on the expansion card. At least you will be able to get 576kB of total memory (assuming the rest of the chips are ok!). You will have to change the switches on the card to change the amount of installed memory. Settings are below:

http://www.thegreenhouse.us/th99/i/A-B/50651.php

Chances are, the SixPakPlus card is absolutely fine ;) I would expect it needs a new battery by now, but that is a simple fix. The RTC is a very useful addition, Modem7 has the drivers on his web page.
Click to expand...

Thanks for that link, very VERY helpfull.

I'll be working on this card tonite to see how much memory I can manage to make usefull. It was only a single chip from the motherboard that went bad, I tried replacing it with a single chip from the sixpakplus card and it wouldnt work untill I replaced the whole bank with identicle chips.


Im going to be on the hunt for an 8 bit floppy controller... & cable... & drive probably, I have no way to test the ones I have now. Im also going to be looking for a hard drive solution, the hard card sounds nice or perhaps.. MFM or RLL or... something I dont care.. I just want a hard drive ;)

I also plan to get the case powder coated to make it look like new, will need some sanding to remove the rust splotches.
 
Regarding the hard drives, as you appear to have the original 63W power supply you will need to swap it for a more powerful one to be able to power the drive. XT's had 130W PSUs. With a hard card, you should be able to get away with the original.

I found that car paintwork scratch remover paste works a treat in making the case look like new. My 5150 was really rather battered when I had it, but now looks fantastic :)

The setup of cards I have in my 5150 are as follows:

Slot 1: 20MB SCSI Hard card
Slot 2: WD8003 network card with AUI>RJ45 Transceiver
Slot 3: QuadRam 384kB memory expansion, RTC and Serial
Slot 4: Hercules graphics card with Parallel (connected to IBM 5151 monochrome display)
Slot 5: IBM Floppy card

There are two full-height 360kB floppy drives. It runs PC-DOS 3.1 :)

I also have the original IBM monochrome display card so I can return the machine to factory very easily.
 
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dongfeng said:
Regarding the hard drives, as you appear to have the original 63W power supply you will need to swap it for a more powerful one to be able to power the drive. XT's had 130W PSUs. With a hard card, you should be able to get away with the original.

I found that car paintwork scratch remover paste works a treat in making the case look like new. My 5150 was really rather battered when I had it, but now looks fantastic :)

The setup of cards I have in my 5150 are as follows:

Slot 1: 20MB SCSI Hard card
Slot 2: 3Com 3C503 network card with AUI>RJ45 Transceiver
Slot 3: QuadRam 384kB memory expansion and RTC
Slot 4: Hercules graphics card (connected to IBM 5151 monochrome display)
Slot 5: IBM Floppy card

There are two full-height 360kB floppy drives. It runs PC-DOS 3.1 :)

I also have the original IBM monochrome display card so I can return the machine to factory very easily.
Click to expand...

I dont spose there is a single 8-bit card that would handle floppy and a hard drive for me? hehehe
 
JDT said:
I dont spose there is a single 8-bit card that would handle floppy and a hard drive for me? hehehe
Click to expand...
They exist of course. Even if you particularly wanted a MFM hard drive, there is for example the Longshine LCS-6220 - an 8 bit combined MFM/floppy controller. But I think you'll just have to take what you can get. 8 bit boards can be found on eBay.
 
There might be, but I haven't seen one. It will also depend if you want to stick with authenticity by using original IBM cards where possible! I think the combination of cards I listed above are pretty much a perfect 5150 system, without losing any originality :)

If you need to put in lots of cards, an XT has 8 slots ;)
 
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Yes, the norm with 8 bit cards is that hard disk controllers are dedicated cards. Cards such as the LCS-6220 will be rare.

I too like to keep my machines 100% IBM, and therefore if I had a spare ST412, I'd go for the 10MB controller at:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=220091421851

There's another 8 bit HDD controller on eBay presently: http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=280093835989
Possible problem 1: Always a gamble with those 'sold as is' items.
Possible problem 2: Looks like a very early controller that like the IBM 10MB controller, only supports 1 type of drive.
 
dongfeng said:
There might be, but I haven't seen one. It will also depend if you want to stick with authenticity by using original IBM cards where possible! I think the combination of cards I listed above are pretty much a perfect 5150 system, without losing any originality :)

If you need to put in lots of cards, an XT has 8 slots ;)
Click to expand...

Authenticity & Originality arent my top priorities. As such, I will take what I can get ;)
 
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