Tasman Printer Interface for ZX Spectrum

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1024MAK
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Location: Looking forward to summer in Somerset, UK...

Tasman Printer Interface for ZX Spectrum

Post by 1024MAK »

A draft schematic is attached:
Tasman Printer Interface for ZX Spectrum_draft01b.png
Tasman Printer Interface for ZX Spectrum_draft01b
(167.16 KiB) Downloaded 378 times
When I have sorted myself out, I will upload various photos of this interface ;-)

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
User avatar
1024MAK
Posts: 5087
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Tasman Printer Interface for ZX Spectrum

Post by 1024MAK »

Attached are two BASIC programs.

Tasman Listing 1 TasmanTst was used by me to test the interface. It flashes LEDs (via current limiting resistors) so that I could check that my schematic was correct, that I had the correct I/O port addresses and to confirm that the 8255A chip was working correctly.

Tasman Listing 2 TasmanPnt is a BASIC program that sends some text to a dot matrix printer to test that the interface can indeed work as a printer interface.

Both are in plain text files and also in a TAP file (which is zipped up) so that they can be loaded into a real ZX Spectrum.

Code: Select all

Interface I/O Port Addresses:

Function Decimal Hex  Binary     Used for
======== ======= ===  =========  =================================================
Port A      59    3B  0011 1011  Bit D0 used for the /STROBE signal to the printer
Port B      63    3F  0011 1111  Bit D0 used for the BUSY signal from the printer
Port C     123    7B  0111 1011  8 bit data byte to the printer
Control    127    7F  0111 1111  8255A control port
Mark
Attachments
Tasman_Printer_IF_Test.tap.zip
Tasman_Printer_IF_Test.tap
(1.56 KiB) Downloaded 250 times
Tasman Listing 2 TasmanPnt.txt
Tasman Listing 2 TasmanPnt
(1.37 KiB) Downloaded 246 times
Tasman Listing 1 TasmanTst.txt
Tasman Listing 1 TasmanTst
(1.85 KiB) Downloaded 311 times
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
User avatar
1024MAK
Posts: 5087
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Tasman Printer Interface for ZX Spectrum

Post by 1024MAK »

Output from a real Epson LX-300 dot matrix printer (with faded ribbon)
Output from a real Epson LX-300 dot matrix printer (with faded ribbon)
IMG_5238.JPG (101.87 KiB) Viewed 3329 times
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
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