iSys V8.5e Thermal Printer - Manual (Page 59)

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C. APPENDIX
CENTRONICS INTERFACE BOARD
The new Centronics adapter (rev1-2) implements some improvements over the previous (rev1-1) adapter card.
These include:
a. Rev 1-2 cards will accept either of the two data transfer methods described below automatically; no
switches or jumpers required.
b. Reliable data transfers using up to 40 ft length of shielded cable.
c. Rev 1-1 adapter cards exhibit inconsistent data transfer with newer generation PC.’s equipped with high
speed integrated Centronics parallel ports.
The following are two transfer formats that can be used with the optional V8.5E Centronics parallel adapter:
1) Standard transfer format
To place the V8.5E Centronics adapter in raster mode, the following 3 bytes (hex) must be sent to the
Centronics adapter card:
1B, 2A, 00
Once these 3 bytes are sent, rastered plot data can be sent to the plotter as follows:
V8.5E bytes/scan menu setting bytes/scan raster data
b1 216
b2 264
g1-g4 1728
Once the V8.5E Centronics adapter is set to raster mode it will remain in raster mode until the init line of the
host Centronics port is pulsed or the plotter power is cycled. This will return the adapter to print mode.
2) Enhanced transfer format
For more flexibility, a 6 byte header can be sent before each scan of rastered data. This header allows
variable bytes/scan plotting. The Centronics adapter also returns to print mode at the end of every scan
using this transfer method. This allows the five 1B, 4X commands or the standard ASCII control codes listed
below in section 3 to be used during plotting. The format of the 6 byte header is:
1B 2A 72 XX YY 01 where XX = high byte of the
number of bytes/scan
YY = low byte of the
number of bytes/scan