ZX Printer: Difference between revisions

Revision as of 22:10, 25 November 2012

The ZX Printer prints on a roll of special metallised paper; it has a stylus which passes an electric current through the paper and blackens the surface.

It responds on any port with A2 set low.

	Bit
	7	6	5	4	3	2	1	0
Read	Paper start latch	0	1	1	1	1	1	Next pixel latch
Write	Stylus power					Motor Power	Motor speed

Paper start latch: raised when the stylus reaches the start of the paper, or when stylus power is turned on.
Next pixel latch: raised when the stylus reaches the next pixel (approximately every 250 T-states when motor fast)

Stylus power: 0=off, 1=on
Motor power: 0=run, 1=stop
Motor speed: 0=fast, 1=slow (no effect if motor stopped)

Any I/O write to the printer also resets the latched signals.

BASIC commands

COPY (Z) will print the current screen (pixel data only; the state of attributes is ignored, so you might get some bits of your picture inverted).
LPRINT (Extend-C) acts like PRINT but sends output to the printer.
LLIST (Extend-V) acts like LIST.

@@ Line 1: / Line 1: @@
 The '''ZX Printer''' prints on a roll of special metallised paper; it has a stylus which passes an electric current through the paper and blackens the surface.
-It responds on any port with a<sub>2</sub> low, such as 0xFD.
+It responds on any port with A2 set low.
-==OUT effects==
+{| class="wikitable" style="text-align: center;"
-* d<sub>7</sub> - stylus power: 0=off, 1=on
+|-
-* d<sub>2</sub> - motor power: 0=go, 1=stop
+! rowspan="2" style="width: 5em;" | &nbsp;
-* d<sub>1</sub> - motor speed: 0=fast, 1=slow (no effect if motor stopped)
+! colspan="8" | Bit
-Any OUT to the printer also clears the latched IN signals (see below).
+|-
+! style="width: 5em;" | 7
+! style="width: 5em;" | 6
+! style="width: 5em;" | 5
+! style="width: 5em;" | 4
+! style="width: 5em;" | 3
+! style="width: 5em;" | 2
+! style="width: 5em;" | 1
+! style="width: 5em;" | 0
+|-
+! style="height: 5em;" | Read
+| Paper start latch || 0 || 1 || 1 || 1 || 1 || 1 || Next pixel latch
+|-
+! style="height: 5em;" | Write
+| Stylus power || || || || || Motor Power || Motor speed ||
+|}
-==IN response==
+* Paper start latch: raised when the stylus reaches the start of the paper, or when stylus power is turned on.
-* d<sub>7</sub> - latched '''1''' when the stylus reaches the start of the paper
+* Next pixel latch: raised when the stylus reaches the next pixel (approximately every 250 T-states when motor fast)
-* d<sub>6</sub> - pulled '''0''' if ZX Printer connected
-* d<sub>0</sub> - latched '''1''' each time the stylus reaches the next pixel (about every 250T when motor fast)
+* Stylus power: 0=off, 1=on
-All other bits '''1'''.
+* Motor power: 0=run, 1=stop
-Note that IN does ''not'' clear the latched signals.
+* Motor speed: 0=fast, 1=slow (no effect if motor stopped)
+Any I/O write to the printer also resets the latched signals.
 ==BASIC commands==

ZX Printer: Difference between revisions

Revision as of 22:10, 25 November 2012

BASIC commands

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