Sony DTL-H2000 BIOS (1994)

[Administrator]

A DTL-H2000 BIOS dump was successfully completed. It has never been released before, so here it is.
Thanks to goes out to Shane McRetro

It was in placement of a 1994 dated H2000. Here are some interesting ASCII strings from the binary:

Code: Select all

PS-X Realtime Kernel Ver.2.5.Copyright 1993,1994 (C) Sony Computer Entertainment Inc. ......PS-X ROM monitor Ver.2.3.Copyright 1993,1994 (C) Sony Computer Entertainment Inc.

BOOTSTRAP LOADER Type C Ver 2.1   03-JUL-1994.Copyright 1993,1994 (C) Sony Computer Entertainment Inc.

Effective memory must be 2/8/16 MBytes

$Id: kmem.c,v 1.1 1994/01/24 09:25:31 kaol Exp $ : .Copyright (C) by 1993, 1994 Sony Computer Entertainment Inc.

BR3000 SONY_PSX4.00

PSY-Q (C) 1994 S N Systems Limited

DOWNLOAD:

27-07-94.bin

[nocash]

That's really old, and contains several differences to later retail modes. Some added/removed kernel functions - and apparently absolutely no support for memory cards. Is that a known issue that applies to all DTL-H2000 boards? Or is there some upgrade for it with memory card support?
(Upgrade could be either a EPROM with newer Kernel version, or some file on the PC harddisc with a newer Kernel that could be loaded into PSX RAM.)

Or in other words: Is there some way to run retail games on the DTL-H2000? It doesn't really look so.

Aside from 8Mbyte Main RAM it does also seem to have 1MByte RAM at 1FA00000h. And several I/O ports at 1F8020xxh:

It's using the "DIP Switch" register that was mentioned in some docs, so we know where that DIP Switch stuff came from. Though I still don't know what it is meant to be since the DTL-H2000 boards don't seem to have any DIP switches (aside from things PC I/O port select switches and DMA/IRQ jumpers, which are unlikely to be mapped to a PSX register).
Whatever that DIP Switch thing is about, it's something important (some sort of "boot mode" selecting handled almost immediately after Reset).

TTY does exist, but it seems to use different I/O ports as the "duart" stuff in retail bioses.

There are also some extra devices:
* sim - CDROM Sim (that is apparently what the Castlevania retail version is trying to access)
* mwin - Message Window (some extra feature, or maybe that's just the second TTY channel?)
* sio - SIO console (code for that device exists, but it seems to be unused)

The seem to be no GUI (like Sony logo, Audio player, Memory Card manager). And there's no character set. But there seems to be some command prompt based debugger and disassembler - right in the PSX BIOS (rather than in the PC software).

[Administrator]

This is what you're after. It is the RAM patch that must be ran every single time you run a CPE. It would be great to merge this with the BIOS since it would eliminate the need to keep loading SNPATCH.CPE every time someone would like to test their compiled CPE as it would make the execution process a little quicker, though that is going to be quite difficult to accomplish.

SNPATCH.CPE

'sim' may be the 'CD Emulator System' (DTL-H2020) card that lets developers use a HDD to run their program (pictures below). It has a ribbon cable that plugs into the DTL-H2000 and then I suspect that then goes to a SCSI HDD either using that larger onboard IDE connector for an internal solution, or by using the external connector on the back for a external HDD solution (see the last image for the 'Packing List'. It seems that it's missing the 34 way cable that connects it to the H2000). Everything would be explained about it in the Psy-Q documents nevertheless.

[Administrator]

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