Acorn Electron Project Expansions Sound Cartridge

[mark71]

Hi All

I was asked today for some info on the Project Expansions Sound Cartridge for the Acorn Electron, as i have one from when i bought it new in the late 80's, for future posterity and for those who want to replicate this. Here are some pictures and information that i have.

Attached are some images of the board/Rom image and a copy of the manual supplied, i paid £39.95 in 1988 still have the receipt and correspondance form Chris Rugde apoligizing for the delay in shipment.

I can buzz out the missing links if people are interested, I would like to learn KiCad but the day job limits my time.

Mark

[Pernod]

Attached are some images of the board/Rom image and a copy of the manual supplied, i paid £39.95 in 1988 still have the receipt and correspondance form Chris Rugde apoligizing for the delay in shipment.

Thanks for these, it fills in a missing part of the puzzle. We already have ROM versions 1.00 and 3.0, so this 2.0 should complete the set

[jms2]

Excellent - just what I was looking for. It's a bit simpler than I expected actually.

The V2 rom uses the same hardware addresses as V1 - data at $FC84 and enable at $FC85. The (very small) photo of the hardware on acornelectron.co.uk shows an integrated speaker, so I guess that was one of the v3 changes.

[Pernod]

I can buzz out the missing links if people are interested, I would like to learn KiCad but the day job limits my time.

The Sound Expansion v3 cartridge maps the ROM to bank 13, using the OE2 line. Could you let me know which bank(s) the v2 ROM is mapped to?

[roland]

Is it worth to rebuild this sound cartridge? The SN76489 seems very cheap on AliExpress.....

[jms2]

That’s the plan Roland, using that chip.

[mark71]

I can buzz out the missing links if people are interested, I would like to learn KiCad but the day job limits my time.

The Sound Expansion v3 cartridge maps the ROM to bank 13, using the OE2 line. Could you let me know which bank(s) the v2 ROM is mapped to?

Same as V3 13, screen shot using the plus 1

[Pernod]

Same as V3 13, screen shot using the plus 1

Thanks, I'll update my emulation.