Need help when use isa-to-usb card in IBM 5160!

[pietja]

I have looked at the schematic for this board and the little chip in the bottom left is the address decoder.
It puts the ISA to USB chip at I/O address 260h.

However it also partially decodes the address for the onboard ROM.
It does not check address bits 19 and 18 so that puts the ROM at the following 4 address in memory.

D8000-DFFFF
98000-9FFFF
58000-5FFFF
18000-1FFFF

That means the last 3 addresses are an alias for the main location and puts them in normal memory.

So that the 5160 is only counting to 96Kb of memory is because that is where it hits the first rom alias.

If you want to be able to boot from this card it means you have to put the rom chip in another card with a fully functional address decoder

[SUB]Attached are all the translated files from the manufacturer of the chip. (rom bios, .sys driver, schematic and more)[/SUB]

 

[ineverland]

Thanks pietja! Your post exactly explains this problem.So because of a mistake in design,the rom mapped to 4 addresses,and disturbs normal system memory.Now what can I do with this card?Why they don't decode all the address?The seller told me it can be used to boot a system,why he say that?Should I return the card to it's seller?Is this card totally useless?

 

[pearce_jj]

I wonder if it is designed for eg PC/104, rather that the PC/XT.

But it isn't useless. You just need to move the ROM somewhere else (or we run our own corrected PCBs). I have a ROM board you could use, or as I posted a few posts up, you could move the ROM to a NIC.

 

[ineverland]

It's very clever to load the rom with other cards, If I put the rom in a NIC ,Can the system boot from usb?

 

[jh1523]

It's very clever to load the rom with other cards, If I put the rom in a NIC ,Can the system boot from usb?

As long as the ROM is mapped to a usable address, it doesn't matter how it is physically attached to the system. In my XT clone I have EPROMS with the XT-IDE universal BIOS and a floppy controller BIOS plugged into sockets into the motherboard, just because they were there. They work very well.



A dump of the ROM would be useful; I'm trying to see if I can replicate this card (with improved address decoding )


(edit) It looks like there is a dump of the ROM already in the package posted in #21 above. Would probably still be useful to dump and post the one you have just in case there are any changes.

 

[pietja]

... Should I return the card to it's seller?Is this card totally useless?

If you're handy with electronics and soldering you can add a chip for the 2 missing bits to fix the bad address decoder.
The other option is to put the rom in another card.

I'm trying to see if I can replicate this card (with improved address decoding )

Everything you need is in the link i posted here.
http://www.vintage-computer.com/vcf...ISA-Bus-it-is-possible!!!&p=377910#post377910
It contains two versions of the board with and without a GAL to do the address decoding but both are missing bit 18 and 19.
If you have Altium Designer you can even open the original schematic and pcb files.

 

[Malc]

It runs dos 2.1, and dos driver can run on 8088 as Dca2 said in another thread.
I do have a 3.5" floppy drive,but the cables are different,I don't know what kind of cable can do that,Do you have a picture?Many thanks!

See this page on Modem7's site re: booting from 720k, I just had a quick look in the zip that pietja posted and in the readme it states that ch375dos.sys supports DOS 3.x to 7.x

 

[Malc]

..... (or we run our own corrected PCBs).....

I second that and maybe a CF adapter with a USB header onboard ?

 

[jh1523]

If you're handy with electronics and soldering you can add a chip for the 2 missing bits to fix the bad address decoder.
The other option is to put the rom in another card.


Everything you need is in the link i posted here.
http://www.vintage-computer.com/vcf...ISA-Bus-it-is-possible!!!&p=377910#post377910
It contains two versions of the board with and without a GAL to do the address decoding but both are missing bit 18 and 19.
If you have Altium Designer you can even open the original schematic and pcb files.

Actually I'm thinking of something more fancy, with selectable addresses for the ROM and maybe even for the USB chip i/o

 

[pietja]

Is this card totally useless?

This is how you can mod the card so the address decoder works.
It involves soldering 1 74LS11 chip to the card.

Actually I'm thinking of something more fancy, with selectable addresses for the ROM and maybe even for the USB chip i/o

If the bios provided by the manufacturer works with the 8088 and 8086 you still need to change a few bytes in the bios if you want to use it on a different i/o address but that is all mentioned in the readme.

 

[jh1523]

This is how you can mod the card so the address decoder works.
It involves soldering 1 74LS11 chip to the card.
View attachment 25936


If the bios provided by the manufacturer works with the 8088 and 8086 you still need to change a few bytes in the bios if you want to use it on a different i/o address but that is all mentioned in the readme.

I was about to say that a few bios changes may be needed. Going through the disassembly now.
(edit) see I should read READMEs first. The I/O address is in the BIOS file at 0x38-0x39. Duh!
(edit2) it would be cool if we could change that dynamically. I have an idea or 2 on how to do that.

 

[ineverland]

See this page on Modem7's site re: booting from 720k, I just had a quick look in the zip that pietja posted and in the readme it states that ch375dos.sys supports DOS 3.x to 7.x

According to a sticky thread IBM-PC-XT-5160-BIOS-versions there are four versions of bios,only the last two support 720k floppy.I'm afraid mine is not that version,you can see the U19 chip picture I upload before ,it has a part number 5000027.I guess boot from.3.5" 720k floppy may not work.

 

[bobba84]

ignore this post lol

 

[ineverland]

This is how you can mod the card so the address decoder works.
It involves soldering 1 74LS11 chip to the card.
View attachment 25936

Thank you for your advice.I never soldered anything before ,that's why I didn't choose XT-IDE cards,they have no working card on sale.But this time I want have a try.Please taught me how to do it if you have time :super:
(edit)Is there a another way to do it ,like reporgram or replace the little chip in the bottom left?

 

[ineverland]

I was about to say that a few bios changes may be needed. Going through the disassembly now.
(edit) see I should read READMEs first. The I/O address is in the BIOS file at 0x38-0x39. Duh!
(edit2) it would be cool if we could change that dynamically. I have an idea or 2 on how to do that.

Please share your ideas ,maybe this card can come to life with your help.

 

[ineverland]

I make a phone call to the ch375 technology support,He claims an interesting thing.
In the picture below

the line "Press CTRL to start E-DISK" is printed by the card bios as he said.
So the bios rom is called by system,but the card can't recognize the usb disk.
I'm confused now,If this line is printed by the bios rom,why I can't find these words in the bios rom file?
(edit)it's ok if system can boot with 96kb memory recognized.
what's the meaning of these lines?
"
F6400 ROM
F8400 ROM
FA400 ROM
FC400 ROM
"
ERROR (RESUME =F1 KEY)
who print these lines?

 

[ineverland]

Engineer from WCH(ch375 producer) gives me a new bios rom file,it's different from the one pietja uploaded before.
There are words "Press CTRL to start E-DISK" too.

 

[pearce_jj]

I wonder if they might make the BIOS open source.

 

[modem7]

what's the meaning of these lines?
"
F6400 ROM
F8400 ROM
FA400 ROM
FC400 ROM
"
who print these lines?

The lines are produced by the BIOS ROM on the 5160 motherboard, specifically the power-on self test (POST) component of it.

Why? Because CH375ROM.BIN is not meeting a requirement of the 5160's POST.

Background: The information at [here].

Requirement: The IBM 5160 (and final 5150) POST is coded such that it requires that the 'ROM size' byte in BIOS expansion ROMs be a multiple of 2 KB.

CH375ROM.BIN is 3 KB sized, and accordingly, its third byte of '06' indicates 3 KB. If 'ch375 technology support' will modify things so that everything (code size, third byte, checksum byte) reflects 4 KB, then the 'xxxxx ROM' lines will disappear.

How do I know this? Because we have seen this symptom before, at [here].

 

[ineverland]

The lines are produced by the BIOS ROM on the 5160 motherboard, specifically the power-on self test (POST) component of it.

Why? Because CH375ROM.BIN is not meeting a requirement of the 5160's POST.

Background: The information at [here].

Requirement: The IBM 5160 (and final 5150) POST is coded such that it requires that the 'ROM size' byte in BIOS expansion ROMs be a multiple of 2 KB.

CH375ROM.BIN is 3 KB sized, and accordingly, its third byte of '06' indicates 3 KB. If 'ch375 technology support' will modify things so that everything (code size, third byte, checksum byte) reflects 4 KB, then the 'xxxxx ROM' lines will disappear.

How do I know this? Because we have seen this symptom before, at [here].

Thank you modem7,Things are getting more clearer ,I reproduce the same error in an IBM XT emulator called "PCE".
I load the CH375ROM.BIN at 0xd8000,it's can be done with cfg file.
I test two xt bios:ibm-xt-1986-05-09.rom/ibm-xt-1982-11-08.rom.
ibm-xt-1986-05-09.rom didn't produce xxxxx ROM,as modem7 said in XT-FDC project.

ibm-xt-1982-11-08.rom behaves exactly the same as my 5160.

CH375ROM output a line "Press CTRL to start E-DISK",so I think even the rom size byte is 3kb (not a multiple of 2 KB),XT bios still called the rom bios.
But pressing CTRL key makes no difference,ROM BIOS seems not doing anything after CTRL been pressed.System continue to boot from fdd or hdd or BASIC rom.

this is the 2k version BIOS ROM pietja uploaded output.

look inside the rom files,you can find the 3kb version bios is v1.5,the 2kb version bios is v1.3.