Has anyone managed to open the unit to look for a battery? Similar to the leaking battery in SC-55 thread.

I couldn't manage it...

Actually I might post in that thread instead.

Keropi, I like the SCB-7 & MPU-401AT pairing. Question about the SCB-7: does it have a 16 or 18 bit DAC? Thanks.

Edit:
Is the SCB-7's ROM 2 or 4 MB in size? Thanks.
End Edit.

No idea I don't have the scb7 anymore... But I know it has a 4mb sample rom. It was nice for games!

Thanks a lot. BTW, please can someone tell me what the ICs are, on the Roland SCB-7, and also on the Roland MPU401-AT card. Thanks.

I can answer the 401AT question - I think correctly 🤣
- top is mcu
- bottom left some work sram
- bottom right a bus interface chip

Thanks a lot. Re: the SCB-7, I wonder if the two smaller Roland chips contain the 4MB ROM (2MB each?) wavetable sound sample set?

retro games 100 wrote:

Thanks a lot. Re: the SCB-7, I wonder if the two smaller Roland chips contain the 4MB ROM (2MB each?) wavetable sound sample set?

The Roland chip on the top left (IC9) is most probably a ROM. The one on the lower right is most probably not. I've never seen ROMs with 80 pins. I'd think it is the bus interface chip.

The Toshiba and the Hyundai chips are both SRAMs.

The board was produced in 94, all chips have 94 date codes.

Thanks a lot. BTW, do you happen to know when the MPU401-AT card was made? Also, sorry, but what exactly is SRAM? Finally, why is it called "401"? What does that nunmber mean? Thanks.

SRAM is "Static RAM" as opposed to DRAM "Dynamic RAM". SRAM is fast and expensive per bit and mostly used in caches and as RAM for controllers like such sound chips. DRAM is inexpensive per bit but in general slower as SRAM. It is used as RAM for PCs and servers. You can find it on SIMMs and DIMMs.

Regarding the date codes. This is usually handled differently by each chip manufacturer. Many of use the format YYWWxxxxx, where YY is the year (i.e. 94), WW is the week of the year (i.e. 38), and xxxx some arbitrary number of variable lenght (probably the lot number and/or the factory which produced it). Other manufacturers us YWWxxx, where the Y is only the last digit of the year (i.e. 5 for 1995). An then there some that use a completely different scheme that is can only be decoded using their datasheets.

Now if you look over all the chips on a board, and if you consider that they are usually produced around the same time, and if you find a lot such numbers like 9438213, 9435123, 940312322 on your board, you can be pretty sure that the board was produced in 94 or early 95, but not in 93 or so.

Regarding the MPU-401 read this https://en.wikipedia.org/wiki/MPU-401

retro games 100 wrote:

Question about the SCB-7: does it have a 16 or 18 bit DAC? ... Is the SCB-7's ROM 2 or 4 MB in size?

IC10: NEC μPD6376 - 2-channel, 16-bit DAC

IC9: Fujitsu MB838000B - 1 MB Mask ROM, with 2 MB-equivalent (companded) content

Thanks a lot. So the SCB-7 differs from the SCB-55, in as much as the SCB-7 has 2MB wavetable ROM sample (compounded) content, and the SCB-55 has 4MB wavetable ROM sample (compounded) content? Thanks.

retro games 100 wrote:

So the SCB-7 differs from the SCB-55, in as much as the SCB-7 has 2MB wavetable ROM sample (compounded) content, and the SCB-55 has 4MB wavetable ROM sample (compounded) content?

The SCB-55, like the SC-55 and SC-55mkII, has an equivalent 6 MB of companded content.

SC-55 Problems

Thanks. BTW, what does companded mean? (Do you mean compressed?) Thanks.