SD512 with HB201P stucks

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By Lao Mu

Supporter (13)

Lao Mu's picture

27-08-2018, 12:15

Pentarou wrote:

So you removed the chip? But why the socket?

With the socket it is easy to get back to the original status with Utility ROM. In cas I sell that one day without the SD512 or so.

For your boot problem:
Nextor needs 128Kb, so the switches have to be in the Mapper position, otherwise it will boot in disk basic.

Switches had been in Mapper position ...just the SD was not inserted.

If it still doesn't work, try to format the SD card in the MSX with this procedure:
When you boot keep the "1" key pressed until you get to the basic prompt, then use "call fdisk".
Then move the SD card to a PC and copy the files.

I will give this a trial later.

By Xdabler

Supporter (14)

Xdabler's picture

16-12-2021, 15:27

odaman68000 wrote:

Hi, I had same problem with HB-101.
Also HB-201 has original firmware(simple application), and it prevent the booting of SD513.

I tried anything, but there’s only one way that disabling the firmware with hirdware modification.
MSX-Bios and application firm are on different ROM chip, so only application firm ROM should be disabled.
Very easy and simple modification, but ROM pin assign and hardware knowridge is required...

Hello

I know I am responding to a post from years ago.I have a msx hb101p and the sd512 is not working. Do you remember the modifications you made to make it work?

Thanks

By odaman68000

Rookie (25)

odaman68000's picture

29-12-2021, 10:45

Hi Xdabler,

Quote:

know I am responding to a post from years ago.I have a msx hb101p and the sd512 is not working. Do you remember the modifications you made to make it work?

I would like to mention again, HB-101 needs some hardware modification to disable internal firmware.
On HB-101/201, Sony's custom firmware works at first and it prevents booting from SD-512.
You can see two ROM chips on HB-101/201, one is MSX-BIOS/BASIC 32KB ROM and other is 16KB of custom firmware.

The best way is : cut all pins on 16KB custom firmware ROM chip. Now a days there're no good points to work with custom firmware.

I hope this helps. Smile

By gdx

Enlighted (5984)

gdx's picture

29-12-2021, 10:57

Do not cut the pins. It's pretty easy to desolder with a good pump.
But before you desolder it, wait a bit, I'll see what I can do for you.
Tell me what is your MSX and SD-512 model exactly.

By gdx

Enlighted (5984)

gdx's picture

29-12-2021, 16:41

I found a simple method to bypass the HB-201 firmware without to remove the ROM.
You have the SD-512 v1 or v2? Where can I download the latest firmware? I need it to add the bypass routine.

Edit: I made a patch for following SD Mapper firmwares.
https://github.com/fbelavenuto/msxsdmapper/tree/master/Driver
https://github.com/fbelavenuto/msxsdmapperv2/tree/master/Driver

Temporary download link:
https://1fichier.com/?e6yqmvqxtrdoo3pfndt6

Tell me if it fits.

Important: In case of problem, you must have another disk interface to return to the previous firmware.

This patch inserts the folowing routine at the address 47E0h (7E0h in the file).

	push	af
	in	a,(0a8h)
	push	af
	or	0ch
	out	(0a8h),a
	ld	a,(404Eh)
	cp	048h		; 'H'
	jr	z,JUMP
	ld	a,0c9h
	ld	(4027h),a
JUMP:
	pop	af
	out	(0a8h),a
	pop	af
	jp	40F6h

By gdx

Enlighted (5984)

gdx's picture

29-12-2021, 17:27

I deleted the patch because I forgot that the DOS2 needs memory expansion and therefore the firmware no longer fits in the internal RAM. It will take a little longer for the patch to be functional.

By gdx

Enlighted (5984)

gdx's picture

30-12-2021, 08:40

Yesterday, I wanted to do it too quickly. Here is the fixed patch.

Patch to bypass the HB-201 firmware (Nextor 2.10b2).zip

The patch inserts the folowing routine at the address 7FA0h (3FA0h in the file).

RDSLT	equ	0000Ch		; Read a byte in a slot
WRSLT	equ	00014h		; Write a byte in a slot

	push	hl
	push	de
	push	bc
	ld	a,3		; Slot 3
	ld	hl,4027h	; Address
	call	RDSLT
	cp	048h		; Test 'H'
	jr	nz,JUMP		; Jump if read value is not 'H'
	ld	a,3
	inc	hl		; 4028h
	call	RDSLT
	cp	049h		; Test 'I'
	jr	nz,JUMP		; Jump if read value is not 'I'
	ld	a,3		; Primary slot 3
	ld	e,0c9h		; RET opcode
	ld	hl,402Eh
	call	WRSLT		; Write C9h to bypass the firmware 
JUMP:
	pop	bc
	pop	de
	pop	hl
	jp	40F6h

I tested it as is on the Sunrise CF interface with Nextor v2.10 beta 2, it works fine.

This patch is possible because the firmware of the HB-201/201P is copied to RAM from slot 0 to slot 3 and then executed as a ROM during initialization. So we can insert a cartridge between the two slots which modifies the firmware before it is executed.

To detect the firmware you must find the "HITBIT" text at 4027h address. (My routine tests "HI" only because i think it's enough)

This patch has no effect with the HB-101/101P.

By odaman68000

Rookie (25)

odaman68000's picture

03-01-2022, 11:29

Hi gdx,
I think this patch is better way compared with desolder/cut off all pins of 16KB ROM chip.
But it's little difficult to do it, isn't it? Smile

I already disabled the ROM chip. (connect +5V to CS pin with register.) And it works fine.
But I would like to know how to patch to SD-512. Thanks.

By gdx

Enlighted (5984)

gdx's picture

03-01-2022, 11:44

It's very simple to do. Tell me which firmware you are using and I will tell you if the patch can be applied or not. I think it is, since it is also compatible with Nextor-2.1.1-beta1 for the Sunrise ATA/CF. I can give you the patched ROM directly if you want.

(I think it's better to put a resistor between the 5V and CS.)

By vamprecords

Supporter (2)

vamprecords's picture

09-12-2022, 10:15

@gdx is the patch still available for the Hitbit 201p? i want to use my SD mapper with this machine.

MArtijn

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