CPC464 stuff.

CPC464 related stuff.

Please help me to make this page better. If you make your own interface based on the software and/or hardware on this page, please send me a description of it. You are also welcome to make suggestions and corrections to the material presented here.

AMSSIO.

The Hardware.

AMSSIO - a serial interface for the CPC series of computers

AMSSIO is a RS-232 serial interface for the CPC464 (and 664/6128) and it exists in three different versions which all uses the MC6850 asuncronous communication interface adapter (ACIA) from Motorola.
The first version was based on components from the scrap yard. But the MC14411 is a bit bulky and by now rather old and somewhat hard to find.
The second and third version was an attempt to work around the MC14411.
Version 2 uses a 4060 ripple counter as clock generator. But it can be tricky to make it operate at 2.5 MHz. This was the reason for version 3...
The version 3 uses a 74LS393 to divide the 4 MHz CPU clock by 26 to obtain the 153 kHz for the serial clock (9600 * 16).
I couldn't get the software to receive faster than 9600 :-( But it was at least 4 times faster than the tape transfer rate :-).
All three versions are supposed to use the CPU socket in the CPC. The CPU socket on AMSSIO is meant to be a wire wrap socket. The CPU is removed from the CPC main board. AMSSIO is mounted in the empty socket and the CPU is placed in the 40 pin socket on the AMSSIO.
PLEASE NOTE:
The schematic and pcb in all versions has pin 7 on the 6850 connected to Vcc. This is a bug. Please do *not* connect pin 7 to Vcc.

Version 1.0 Schematic (43KB). Schematic as zipped postscript.

PCB (15KB). PCB files as zipped postscript.

Protel files (11KB). The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

AMSSIO - a serial interface for the CPC series of computers
AMSSIO is a RS-232 serial interface for the CPC464 (and 664/6128) and it exists in three different versions which all uses the MC6850 asuncronous communication interface adapter (ACIA) from Motorola. The first version was based on components from the scrap yard. But the MC14411 is a bit bulky and by now rather old and somewhat hard to find. The second and third version was an attempt to work around the MC14411. Version 2 uses a 4060 ripple counter as clock generator. But it can be tricky to make it operate at 2.5 MHz. This was the reason for version 3... The version 3 uses a 74LS393 to divide the 4 MHz CPU clock by 26 to obtain the 153 kHz for the serial clock (9600 * 16). I couldn't get the software to receive faster than 9600 :-( But it was at least 4 times faster than the tape transfer rate :-). All three versions are supposed to use the CPU socket in the CPC. The CPU socket on AMSSIO is meant to be a wire wrap socket. The CPU is removed from the CPC main board. AMSSIO is mounted in the empty socket and the CPU is placed in the 40 pin socket on the AMSSIO. PLEASE NOTE: *The schematic and pcb in all versions has pin 7 on the 6850 connected to Vcc. This is a bug. Please do not* connect pin 7 to Vcc.**
Version 1.0	Schematic (43KB).	Schematic as zipped postscript.
PCB (15KB).	PCB files as zipped postscript.
Protel files (11KB).	The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

Version 2.0 Schematic (39KB). Schematic as zipped postscript.

PCB (13KB). PCB files as zipped postscript.

Protel files (10KB). The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

Version 3.0 Schematic (34KB). Schematic as zipped postscript.

PCB (12KB). PCB files as zipped postscript.

Protel files (8KB) The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

The Software.

The software for the AMSSIO is in two parts.
One patch for the CPC464 which replaces the original jump block (or at least the relevant part of it). And the second part is a program for the PC, which simulates a disc drive and a printer.

CPC464 programs	Basic loader (125 bytes).	Loader for the binary program.
CPC464 programs	Z80 source (17KB).	Version 1.2 of the jump block patch (Z80 assembler code).*
PC programs	AMSSHELL (3KB).	The Turbo Basic program for the PC (only source code).

*) I've a Z80 assembler for the PC. This is also a Turbo Basic source file. If you want this please feel free to contact me.

History:

980831 First release of the page.

980902 This table added :-).

980902 Output from assembler added to amssio12.zip.

20100501 imported from a rather old backup... ;-)

Back. Last updated May 2010.

Version 2.0	Schematic (39KB).	Schematic as zipped postscript.
	PCB (13KB).	PCB files as zipped postscript.
	Protel files (10KB).	The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

Version 3.0	Schematic (34KB).	Schematic as zipped postscript.
	PCB (12KB).	PCB files as zipped postscript.
	Protel files (8KB)	The above files in Protel Schematic ver 3.31 and Protel Autotrax ver 1.61 formats (zipped).

980831	First release of the page.
980902	This table added :-).
980902	Output from assembler added to amssio12.zip.
20100501	imported from a rather old backup... ;-)