Is possible to emulate SC-155?

[ne3i]

sc55mk2 Test Mode T-3
Button 1 = User
Button 2 = Part Sel
These two buttons should belong to the SC-155
Is possible to emulate the SC-155?

[giulioz]

The SC55 and SC155 are extremely similar, so emulation is definitely possible. The program ROMs, though seems to be different according to the service manual, both the external and the internal MCU one. So you would need to dump the roms to emulate it.

[matt713]

Is possible to emulate the SC-155?

if you own SC-155 unit, then you need to dump the ControlROM - it's in a socket and so it's very simple to do it (read the chip as 27C020 PROM). the MCU is the same as SC-55mk1 v2.00, which is already supported/emulated. so, you just need to make dump of the ControlROM and it should work. essentially, it's few minutes job, to open your SC-155 unit (assuming you own one), take out the chip from the socket and read it with PROM programmer (and then place its content as rom2.bin file in the emulator).

[Grieferus]

On an unrelated note, how did you achieve those colors?

[nikitalita]

I'm having someone with an SC-155 dump the control rom and it should make into mame soon

[matt713]

great, but also make note what are the exact chip marking, because there are at least 2 controlrom versions for SC-155: "R15209361" or "R15209400".

[nikitalita]

looks like R15209361

[nikitalita]

It's dumped

R15209361 Sha256sum: ceb7b9d3d9d264efe5dc3ba992b94f3be35eb6d0451abc574b6f6b5dc3db237b

[giulioz]

@nikitalita great! that's only the external rom though, which it's not enough for emulation

[Gerwin2k]

Giulioz, exactly. As explained here:
#41

[nikitalita]

@nikitalita great! that's only the external rom though, which it's not enough for emulation

It was reported above that the MCU is the same part number as the SC-55mk1 v2.00, R15199799; Is that not dumped?

[Gerwin2k]

It is not publicly available nor is it available to me, and you know ... "please don't ask for roms here".

[nikitalita]

I'm not asking for it, I'm just wondering if it has been dumped by anyone and will eventually get into mame. If not, if nukeykt posts the program they used to dump it, I can probably have the guy program a rom and dump that as well.

[nukeykt]

here's dumper code if anyone interested. Simply burn it to EPROM/Flash, put in place of control ROM, capture MCU data bus + /WR then parse the data
dumper.zip

[ne3i]

On an unrelated note, how did you achieve those colors?

Default color in my desktop computer is not good to my display, I changed the lcd col and modified the back.data

[nikitalita]

here's dumper code if anyone interested. Simply burn it to EPROM/Flash, put in place of control ROM, capture MCU data bus + /WR then parse the data dumper.zip

Thank you! To be clear, you're talking about attaching a logic analyzer to D0-D7 + /WR on here, which would require nine lines, correct?

[nukeykt]

yea, you probably can hook probes to D0-D7 of Control ROM and /WR of RAM

[giulioz]

Other tip that I used to make it work if you have a cheap 8 channels logic analyzer you can do it in two times, first dumping the lower 4 bits and then the rest, so that you can have one line left for /WR. I then used PulseView to decode it and a simple python script to merge them together. Make sure you dump it a couple of times and make sure they are all the same (no errors). You can verify if the dump is correct if the first part is a valid interrupt vector table, similar to the other dumped roms.

[nikitalita]

Other tip that I used to make it work if you have a cheap 8 channels logic analyzer you can do it in two times, first dumping the lower 4 bits and then the rest, so that you can have one line left for /WR. I then used PulseView to decode it and a simple python script to merge them together. Make sure you dump it a couple of times and make sure they are all the same (no errors). You can verify if the dump is correct if the first part is a valid interrupt vector table, similar to the other dumped roms.

Thanks for the tip; I anticipate we may only have access to an 8-channel analyzer. I assume that /WR is the trigger.
Can you post the script that you used?

[giulioz]

out_data = []

with open("tmpl_3.txt", "r") as file:
  lines = file.readlines()

  for line in lines:
    line = line.strip()
    if line:
      last_chars = line[-2:]
      nibble = int(last_chars, 16)
      if nibble <= 0xf:
        out_data.append(nibble)

with open("tmph_3.txt", "r") as file:
  lines = file.readlines()

  i = 0
  for line in lines:
    line = line.strip()
    if line:
      last_chars = line[-2:]
      nibble = int(last_chars, 16)
      if nibble <= 0xf:
        if i >= 0 and i < len(out_data):
          out_data[i] |= nibble << 4
        i += 1

with open("dump3.bin", "wb") as file:
  file.write(bytes(out_data[1:]))

[buffis]

I have a SC-155 and a Saleae Logic Pro 16 (and a Beeprog 2C for roms) and might be able to help out with this some time soonish.

Just to make sure I understand, what's needed is:

• Burn the ROM from dumper.zip to a 27c020 and place it in the control rom socket
• Hook up Probles to D0-7 on the DIP control rom (if they share data bus?)
• Hook up another probe to /WR
• Set /WR as trigger in Logic and start device
• Save capture

Does that sound right?

[giulioz]

Yes, you probably also need to cut the beginning as the stream doesn't start instantly.

[matt713]

so, your SC-155 is not using "R15199799" MCU?! because R15199799 is dumped, SHA1:

76f646bc03f66dbee7606f2181d4ea76f05ece7d

[nikitalita]

so, your SC-155 is not using "R15199799" MCU?! because R15199799 is dumped, SHA1:

76f646bc03f66dbee7606f2181d4ea76f05ece7d

It is a R15199799 MCU.

So there's no need to do this?

[matt713]

if that is the inside of your SC-155, as far as I can tell from that blurry picture it's R15199799.

[Gerwin2k]

so, your SC-155 is not using "R15199799" MCU?! because R15199799 is dumped, SHA1:

76f646bc03f66dbee7606f2181d4ea76f05ece7d

That is the SHA-1 that nukeykt supplied as proper for v2.0. But it is not publicly available AFAIK.
( There is also a bad 32kB mame rom around from 2021 with just repeating bytes. )

Edit, here: #34

[matt713]

IMHO, public or not it doesn't matter at the moment and thus better focus your time and energy on what is not dumped at all.