9 Sep
2014
9 Sep
'14
2:33 p.m.
I saw that the newest versions of the XTIDE Universal BIOS have a way to use the serial
port as a disk drive by connecting to another computer running XP. Since my IBM PC
doesn't currently have any kind of mass storage, this seemed like it could be handy,
even if it might be terribly slow.
I don't have an XTIDE card, but I do have a 3com Etherlink II 3c503 that has an empty
socket. I burned the 12k xtl ROM to a 27c128 and filled the extra space with zeroes. I put
it in the socket and now when the computer boots up I get "DC00 ROM" on the
screen just before it tries to boot from a floppy. However that's it. I tried holding
down the Alt key to get it to give me a menu or scan the serial ports, but nothing
happens.
Is there some trick to making the XTIDE ROM work in the 3c503 socket?
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9 Sep
9 Sep
3:17 p.m.
I have no experience with the 3com card, but I did order my PCBs through
Seeedstudio.
See http://www.lo-tech.co.uk/wiki/XT-CF-lite for more info, although I
applied that guide to
http://www.lo-tech.co.uk/wiki/Lo-tech_ISA_CompactFlash_Adapter_revision_2
since I didn't have the material available to do SMD.
It works perfectly fine though on my 5150.
2014-09-09 19:33 GMT+01:00 Chris Osborn <fozztexx at fozztexx.com>:
I saw that the newest versions of the XTIDE Universal
BIOS have a way to
use the serial port as a disk drive by connecting to another computer
running XP. Since my IBM PC doesn't currently have any kind of mass
storage, this seemed like it could be handy, even if it might be terribly
slow.
I don't have an XTIDE card, but I do have a 3com Etherlink II 3c503 that
has an empty socket. I burned the 12k xtl ROM to a 27c128 and filled the
extra space with zeroes. I put it in the socket and now when the computer
boots up I get "DC00 ROM" on the screen just before it tries to boot from a
floppy. However that's it. I tried holding down the Alt key to get it to
give me a menu or scan the serial ports, but nothing happens.
Is there some trick to making the XTIDE ROM work in the 3c503 socket?
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
--
Kind regards,
Yvan Janssens
Sent using CompuServe 1.22
3:36 p.m.
On Sep 9, 2014, at 12:17 PM, Yvan Janssens <ik at yvanj.me> wrote:
It works perfectly fine though on my 5150.
When it boots on your 5150, do you get anything on screen? Are you able to use the serial
port drives?
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
4:48 p.m.
(this is from memory, so it might not be correct)
It shows a "loading" screen, and allows you to choose an alternate boot
device (depending on it's settings).
Do you know the "load address" from the ROM in the 3com card? I know that
my ROM had a load address of c800, which is pretty common for HDD
controller cards, but the code you have might be loaded at the wrong
address.
2014-09-09 20:36 GMT+01:00 Chris Osborn <fozztexx at fozztexx.com>:
On Sep 9, 2014, at 12:17 PM, Yvan Janssens <ik at yvanj.me> wrote:
--
Kind regards,
Yvan Janssens
Sent using CompuServe 1.22
It works perfectly fine though on my 5150.
When it boots on your 5150, do you get anything on screen? Are you able to
use the serial port drives?
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
6:04 p.m.
On Sep 9, 2014, at 1:48 PM, Yvan Janssens <ik at yvanj.me> wrote:
Do you know the "load address" from the ROM
in the 3com card? I know that
my ROM had a load address of c800, which is pretty common for HDD
controller cards, but the code you have might be loaded at the wrong
address.
Moved the jumpers to put the ROM at C8000, and now when it boots I get a lot of beeping
which sounds like typical PC error beeps, but then it boots from the disk drive like
normal. Searching around to try to figure out what the deal is on the 3c503 ROM socket, I
did find this on the etherboot wiki page:
In one case that we know of, the 3c503 network card, the ASIC
actually returns 2 bytes of 80 80 in the end locations of the
EPROM space.
Got into BASIC on the PC, and sure enough, at 0x1FFE and 0x1FFF there are two 0x80 bytes.
Plus reading past that is only 0xFF. Odd. The socket is a 28 pin socket so it needs at
least a 27128, yet it only passes through the first 8k? I can switch to the 8k XTIDE, but
I'm guessing I will need to do something about the two 0x80 bytes and recalculating
the checksum inside the ROM.
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
11:44 p.m.
On Sep 9, 2014, at 3:04 PM, Chris Osborn <fozztexx at fozztexx.com> wrote:
I can switch to the 8k XTIDE, but I'm guessing I
will need to do something about the two 0x80 bytes and recalculating the checksum inside
the ROM.
And that did it! I moved the checksum byte up and then the two 0x80 bytes cancel
themselves out. Now I get the XTIDE boot screen and I'm able to use the serial drive
stuff. This is great! I've got a hard drive on my PC. It's slow, but it's mass
storage!
Thanks Yvan for the info about putting the ROM at C800!
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
10 Sep
10 Sep
3:27 a.m.
On Tue, 9 Sep 2014, Chris Osborn wrote:
On Sep 9, 2014, at 3:04 PM, Chris Osborn <fozztexx
at fozztexx.com> wrote:
The serial port circuitry on the N8VEM XT-IDE V2 boards contains
provisions for very high speed operation (such as with a USB type RS232
adapter), which would be much, much faster than a standard serial port.
This is fresh in my mind since I recently sourced the remaining parts for
my N8VEM XT-IDE boards. After sitting on my blank boards for a year, I'm
finally about to build them and got most of my parts in just a few weeks
ago. The only odd thing I noticed is that there don't seem to be any DIP
package serial transceivers rated for those speeds (I'm still using one of
the fastest parts available), but I guess they just work anyway.
On a semi-related note, anyone know what happened to the
vintage-computer.com wiki? It used to contain the details on building
these boards, but seems to have disappeared.
http://wiki.vintage-computer.com/index.php/XTIDE_project The N8VEM project
pages don't contain everything that had been on the vintage-computer.com
wiki.
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=XT-IDE%20V2
I can switch to the 8k XTIDE, but I'm
guessing I will need to do
something about the two 0x80 bytes and recalculating the checksum
inside the ROM.
And that did it! I moved the checksum byte up and then the two 0x80
bytes cancel themselves out. Now I get the XTIDE boot screen and I'm
able to use the serial drive stuff. This is great! I've got a hard drive
on my PC. It's slow, but it's mass storage!
Thanks Yvan for the info about putting the ROM at C800!
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fozztexx＠fozztexx.com -
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tothwolf＠concentric.net