motherboards

[[e-mail]]

I was wondering about the days when people made
computers in garages. Have those days actually gone?

Someone told me that it depends on the motherboard
manufacturer, and that even back in the garage days,
motherboards were still a thing. It depends on whether
the manufacturer is willing to release the specs. There
is apparently no "open motherboard standard", but AMD
for some reason are happy to release their specs,
meaning you can possibly write a custom BIOS for their
motherboards. Is that true, and is it sustainable?

Note that I am only interested in writing 32-bit protected
mode code in C, so any BIOS I write would be CSM. I'm
particularly interested in getting INT 14H to talk via
bluetooth to another computer.

Note that I already pursued trying to get SeaBIOS to do
this, but that project didn't seem to be suitable for what
I want, and I want to write something public domain
anyway.

BFN. Paul.

[Rod Pemberton]

On Sat, 16 Oct 2021 01:41:42 -0700 (PDT)

Post by ***@gmail.com
I was wondering about the days when people made
computers in garages. Have those days actually gone?

You mean the motherboard for a brand new computer being designed from
scratch. Yes? I.e., you don't mean assembly of an x86 computer from
components.

IMO, the heyday for that was the 1980s with Byte magazine. This was
during the explosion of 8-bit computers, prior to the development and
standardization of home computer architectures.

Wikipedia thinks those days might still be here, as this page indicates
that there are a bunch of "open source hardware standards," which
includes some motherboards which are "partially" open source:
https://en.wikipedia.org/wiki/List_of_open-source_computing_hardware

There appear to be a few projects there that might have support from
large corporations, such as those by VIA and the Open Compute Project.

I've seen a bunch of projects to recreate older computers using FPGAs
or other programmable logic. There are also a few recreations of
older computers using simple 74xx series logic chips too.

Go to hackaday.com and search for "motherboard". E.g., most are retro
new motherboards, except for the IBM Power9:

-open source NES motherboard
-new Amiga motherboard
-IBM Power9 motherboard
-ATX Amiga 4000 motherboard
-new TRS-80 motherboard
-new XBOX 360 motherboard

You'll probably find a bunch more if you search with Google.

Post by ***@gmail.com
Someone told me that it depends on the motherboard
manufacturer, and that even back in the garage days,
motherboards were still a thing. It depends on whether
the manufacturer is willing to release the specs.

Years ago, I only recall one motherboard manufacturer selling a PC
motherboard for a non-x86 processor chip. My recollection was that
this was Hauppauge. Wikipedia says Hauppauge sold an Intel i860 RISC
PC motherboard.

Of course, Apple sold 680x0 systems, Hewlett-Packard sold PA-RISC
systems, and DEC sold their Alpha systems, but I don't recall being
able to just buy the motherboards for these to assemble them yourself.
There was a large swap market for Macintosh 680x0 motherboards, i.e.,
newer boards installed into older machines.

Today, of course, there should be numerous ARM PC motherboards
available for Android laptops and tablets.

Post by ***@gmail.com
[BIOS]

As for the open-source, open-spec BIOS issue **again**, the best
starting point is probably Phoenix's "System BIOS for IBM PC/XT/AT
Computers and Compatibles". You might also get "IBM Personal System/2
and Personal Computer BIOS Interface Technical Reference". There is
also a link for PhoenixBIOS4.0 manual too.

https://archive.org/download/System_BIOS_for_IBM_PC_XT_AT_Computers_and_Compatibles/System_BIOS_for_IBM_PC_XT_AT_Computers_and_Compatibles.pdf
http://bitsavers.trailing-edge.com/pdf/ibm/pc/ps2/PS2_and_PC_BIOS_Interface_Technical_Reference_Apr87.pdf
http://bitsavers.trailing-edge.com/pdf/phoenix/PhoenixBIOS_4.0_Users_Manual_2000.pdf

HTH

[Rod Pemberton]

On Sat, 16 Oct 2021 06:05:05 -0500

Post by Rod Pemberton
On Sat, 16 Oct 2021 01:41:42 -0700 (PDT)

Post by ***@gmail.com
I was wondering about the days when people made
computers in garages. Have those days actually gone?

You mean the motherboard for a brand new computer being designed from
scratch. Yes? I.e., you don't mean assembly of an x86 computer from
components.
IMO, the heyday for that was the 1980s with Byte magazine. This was
during the explosion of 8-bit computers, prior to the development and
standardization of home computer architectures.
Wikipedia thinks those days might still be here, as this page
indicates that there are a bunch of "open source hardware standards,"
https://en.wikipedia.org/wiki/List_of_open-source_computing_hardware
There appear to be a few projects there that might have support from
large corporations, such as those by VIA and the Open Compute Project.
I've seen a bunch of projects to recreate older computers using FPGAs
or other programmable logic. There are also a few recreations of
older computers using simple 74xx series logic chips too.
Go to hackaday.com and search for "motherboard". E.g., most are retro
-open source NES motherboard
-new Amiga motherboard
-IBM Power9 motherboard
-ATX Amiga 4000 motherboard
-new TRS-80 motherboard
-new XBOX 360 motherboard
You'll probably find a bunch more if you search with Google.

Post by ***@gmail.com
Someone told me that it depends on the motherboard
manufacturer, and that even back in the garage days,
motherboards were still a thing. It depends on whether
the manufacturer is willing to release the specs.

Years ago, I only recall one motherboard manufacturer selling a PC
motherboard for a non-x86 processor chip. My recollection was that
this was Hauppauge. Wikipedia says Hauppauge sold an Intel i860 RISC
PC motherboard.
Of course, Apple sold 680x0 systems, Hewlett-Packard sold PA-RISC
systems, and DEC sold their Alpha systems, but I don't recall being
able to just buy the motherboards for these to assemble them yourself.
There was a large swap market for Macintosh 680x0 motherboards, i.e.,
newer boards installed into older machines.
Today, of course, there should be numerous ARM PC motherboards
available for Android laptops and tablets.

Post by ***@gmail.com
[BIOS]

As for the open-source, open-spec BIOS issue **again**, the best
starting point is probably Phoenix's "System BIOS for IBM PC/XT/AT
Computers and Compatibles". You might also get "IBM Personal System/2
and Personal Computer BIOS Interface Technical Reference". There is
also a link for PhoenixBIOS4.0 manual too.
https://archive.org/download/System_BIOS_for_IBM_PC_XT_AT_Computers_and_Compatibles/System_BIOS_for_IBM_PC_XT_AT_Computers_and_Compatibles.pdf
http://bitsavers.trailing-edge.com/pdf/ibm/pc/ps2/PS2_and_PC_BIOS_Interface_Technical_Reference_Apr87.pdf
http://bitsavers.trailing-edge.com/pdf/phoenix/PhoenixBIOS_4.0_Users_Manual_2000.pdf
HTH

Oh, and don't forget RBIL, Ralf Brown's Interrupt List, which attempts
to document all BIOS and other interrupts. The original has extra files:
http://www.cs.cmu.edu/~ralf/files.html

But, of course, that's just the initial starting point.

Numerous specifications extend and modify the BIOS functionality. Some
specifications modified and extended the BIOS over and over again, with
every new version. There are other specifications which modified the
BIOS in some manner, but perhaps didn't extend interrupts: VESA EDID,
ATA/ATAPI, SMBIOS, SBDS, PCI, APM, PNP, PMM, IPMI, SBFS, USB, etc.

VESA VBE specifications extend Int 10, AH=4fh
APM specifications extended Int 15h
IBM/MS extended Int 13h
Phoenix EDD specifications extended Int 13h
BIOS PNP specifications extended Int 18h, Int 19h
ACPI specifications extended Int 15h, AX=E820h
BBS specifications extended Int 13h, Int 18h, Int 19h

[[e-mail]]

Post by Rod Pemberton

Post by ***@gmail.com
I was wondering about the days when people made
computers in garages. Have those days actually gone?

You mean the motherboard for a brand new computer being designed from
scratch. Yes? I.e., you don't mean assembly of an x86 computer from
components.

I am not familiar with what can be done in garages, I'm
just leery of no-one being able to compete with cartels.

Regardless, there has been a new development. Someone
pointed me to the fact that the emulators accepted TCP/IP
connections, and as such, even under Windows I just need
a small program that connects to qemu etc with TCP/IP and
connects to a Bluetooth device on the other side, which also
seems to also be able to be done with TCP/IP which means
that I can link two PDOS/386 computers via serial port
without requiring the internet.

I need to see what gccwin is capable of doing with regard to
these new libraries (winsock2 it seems).

The computer to computer serial-port-over-bluetooth ability
opens up the Fidonet-like capability I am looking for, and I
think it is more productive to develop that infrastructure
(which is still a mystery - it will be interesting to see what
the existing bluetooth file transfer mechanism looks like),
rather than trying my arm at BIOS manufacture.

I might create my own Linux distribution at some point too,
to support this limited goal of running PDOS/386 including
an effective hardware serial port that will hopefully be able
to cross from our house on one side of the road in the
Philippines to the people on the other side.

BFN. Paul.

[[e-mail]]

Post by ***@gmail.com
Regardless, there has been a new development. Someone
pointed me to the fact that the emulators accepted TCP/IP
connections, and as such, even under Windows I just need
a small program that connects to qemu etc with TCP/IP and
connects to a Bluetooth device on the other side, which also
seems to also be able to be done with TCP/IP which means
that I can link two PDOS/386 computers via serial port
without requiring the internet.

It has now been pointed out to me that an ad hoc Wifi
connection is even better than that, and I don't need to
write any custom Windows program.

So the next goal would be to write something similar to
or exactly the same as UUCP to be run over the serial
ports visible to PDOS/386, between the computers in
rural Philippines.

BFN. Paul.

[[e-mail]]

Post by ***@gmail.com
So the next goal would be to write something similar to
or exactly the same as UUCP to be run over the serial
ports visible to PDOS/386, between the computers in
rural Philippines.

I changed my mind about UUCP and decided to get
Fidonet technology working first (or only) instead.

To that end, I have just got zmodem send and receive
working on PDOS/386. The code (DDC and PDPBBS)
is available in custom.zip at http://pdos.org

Is anyone interested in reviving BBSes using purely
public domain software?

BFN. Paul.

[Scott Lurndal]

Post by ***@gmail.com
I was wondering about the days when people made
computers in garages. Have those days actually gone?

The trend today is to use a FPGA development board to
make your own processor, or recreate an historic processor
(PDP-10, PDP-8, etc.)