Technical
- Uses a 16KB ROM paged into memory at &0000.
- Uses a 8KB static RAM paged into memory at &c000.
- ROM is paged into the range &0000-&3fff when the red button is pressed and the NMI vector is executed.
- Black button pages their ROM into the range &0000-&3fff and executes it at &0000. This checks the ROM version, and clears the extra ram if a CPC6128 BASIC ROM is found.
[code] 0000 f3 di ;; disable maskable interrupts 0001 0100df ld bc,0df00h ;; select upper rom 0 0004 ed49 out (c),c 0006 01817f ld bc,7f81h ;; enable upper rom (mode 1 too) 0009 ed49 out (c),c 000b 31febf ld sp,0bffeh ;; setup stack which is not initialised after reset
000e 3a02c0 ld a,(0c002h) ;; read BASIC ROM version number 0011 fe02 cp 02h ;; CPC6128? 0013 cc2e0c call z,0c2eh ;; erase extra RAM
- this appears to set it up for a reset..
0016 210000 ld hl,0000h 0019 e5 push hl 001a e5 push hl 001b c30038 jp 3800h ;; I think the hardware monitors for address 3800h and if found disables the ROM [/code]
- Uses NMI
- When a write happens to their RAM it appears to write through to the RAM behind??
- Menu code is at offset &3810 and is copied into RAM at &A200.
- Uses port FBF0 (output), FBFF (input). Don't know the exact functions yet.
writing 0 to fbf0 disables it's internal rom.
Pictures
- Hard Micro's Transtape
Front
Back
PCB Top
PCB Bottom
Manual
- Transtape Manual (pdf) (spanish)
Downloads
- Transtape Rom dump (zipped rom file)