Difference between revisions of "Transtape"
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* Uses a 16KB ROM paged into memory at &0000. | * Uses a 16KB ROM paged into memory at &0000. | ||
| − | * Uses a 8KB static RAM paged into memory at &c000. | + | * Uses a 8KB static RAM paged into memory at &c000-&dfff and repeats again at &e000-&ffff. |
* ROM is paged into the range &0000-&3fff when the red button is pressed and the NMI vector is executed. | * ROM is paged into the range &0000-&3fff when the red button is pressed and the NMI vector is executed. | ||
* When the black button is pressed, the ROM is paged into the range &0000-&3fff and executes it at &0000. | * When the black button is pressed, the ROM is paged into the range &0000-&3fff and executes it at &0000. | ||
| Line 31: | Line 31: | ||
* Uses NMI | * Uses NMI | ||
| − | * Doesn't | + | * Doesn't capture the hardware state like the Multiface does. Code in the ROM reads the hardware state which it restores when resuming the program. |
* When a write happens to their RAM it appears to write through to the RAM behind?? | * 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. | * Menu code is at offset &3810 and is copied into RAM at &A200. | ||
| − | * Uses port FBF0 (output), FBFF (input) | + | * Uses port FBF0 (output), FBFF (input). |
| − | + | ||
| + | FBF0 decoding is: | ||
| + | 1111 1011 1111 00xx | ||
| + | |||
| + | FBF0 output: | ||
| + | bit 0 is ram enable/disable state | ||
| + | bit 1 is rom enable/disable state | ||
| + | bit 2 is A10 on RAM | ||
| + | bit 3 is A11 on RAM | ||
| + | bit 4 is A12 on RAM | ||
| + | bits 5-7 are not used. | ||
| + | |||
* The same plastic case is used by the Spectrum version of this interface. | * The same plastic case is used by the Spectrum version of this interface. | ||
Revision as of 15:16, 6 November 2015
A Spanish Hacking Device from HM (Hard Micro, S.A.).
Contents
Technical
- Uses a 16KB ROM paged into memory at &0000.
- Uses a 8KB static RAM paged into memory at &c000-&dfff and repeats again at &e000-&ffff.
- ROM is paged into the range &0000-&3fff when the red button is pressed and the NMI vector is executed.
- When the black button is pressed, the ROM is paged into the range &0000-&3fff and executes it at &0000.
- This checks the BASIC ROM version, and clears the extra ram if a BASIC ROM from a CPC6128 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
- Uses NMI
- Doesn't capture the hardware state like the Multiface does. Code in the ROM reads the hardware state which it restores when resuming the program.
- 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).
FBF0 decoding is: 1111 1011 1111 00xx
FBF0 output: bit 0 is ram enable/disable state bit 1 is rom enable/disable state bit 2 is A10 on RAM bit 3 is A11 on RAM bit 4 is A12 on RAM bits 5-7 are not used.
- The same plastic case is used by the Spectrum version of this interface.
- The spectrum has two switches on the top. One of which chooses load/save.
- In the Amstrad these holes are filled with plastic caps.
Pictures
- Transtape
Front
Back
PCB Top
PCB Bottom
- Transtape Layout, thanks to Jose Leandro
Transtape - PCB Front
Transtape - PCB Back
Transtape - Layout
Manual
Downloads
- Transtape-ROM.zip (Transtape ROM)
- Transtape (eagle).zip (Transtape files for Eagle)
