Epson APL B printer interface

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Are there any informations / Manuals about the Epson APL B printer interface card? I am a beginner in matters Apple IIe and i want to know how that card works and which printers ( only certain Epsons? ) are compatible to that card.

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MarkO's picture
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Re: Epson APL B printer interface

I believe I have Two of these Cards, and One Manual....

Let me check and get back to you...

MarkO's picture
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Re: Epson APL B printer interface

I found the Manual.. Still looking for either Card...

I will see if I can Scan it to Upload it.

MarkO

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Re: Epson APL B printer interface

In general the APL just serves the printers with the 8-bit parallel data to the centronics connector.
So there is no "special function" - except the card has buffer functions like the grappler...

This APL interface was used with any kind of printer with Centronics parallel connection.

It therefor is much more important to get the manual of the used printer!

The manual of the printer displays which kind of control code characters have been used for commands
to the printer ( like bold or italic charset, condensed or not condensed, which character set : US,
french, European or similar - and it also listed the codes used for graphical printing in dot matrix mode )

if hunting for such a printer with centronics connection :

from Epson: FX80,FX85, RX80, RX85, LQ series....

and if from third party manufacturer it´s important to check if the printer is able to work with "emulation mode"
- most printers in those days had the ability by being setup with internal switches to emulate the FX85 or another Epson printer like printers from NEC, Mannesman Tally, OKI, and dozends of other manufacturers ) .....

the only reason for the interface manual is in fact - if the original cable is missing ....
or in the case that the interface offers configuration with DIP switches....
most of the parallel interfaces don´t have such configuration switches...

In such cases it´s required for soldering an replacent of the cable from the interface with the flatrisbon connector
to the centronics connector. This is similar to the problem with the dozends of other printer interface´cards too ....
there was no standard in that days and therefor every flatribbon connector at each interface was different...
so it´s upmost important, when purchasing such a card to have at least a sheet that contains the pinout of the flatribbon connector !

And it´s not a bad idea - if you often use same software - to check in the list of supported printers in the software setup - which kind of printers are supported.... some commercial software even supported laser printers from HP ( which have been common in those days ) like the HP Laser printer 500 and also there it´s the same valid statement: some of the third party laser printer manufacturers offered within their own printers an emulation mode permitting their printers to act like an HP laser printer...

speedyG

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Re: Epson APL B printer interface

Hey Speedy, do these 8-bit parallel interface cards make good controllers for say controlling 8 LED lights/8 transistors/outputting a number from 0-255 ?

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Re: Epson APL B printer interface

If you like to give them such work to do-they will perform in most cases fairly well...
but you should examine the manual of the interface....

Most interfaces perform a correct handshake protocol and will enable you to program
handshaking with the controlled device.... but some of them ( in general the "copy cats" from taiwan have a
"fragmented" handshaking resulting from mistakes while copying the Eprom .....

The performance of handshaking will anyhow be dependent from the content of the EPROM.....
( this of course also means: you are able to write an own EPROM content for the handshaking....

the importance of this is, that in the EPROM there are following contents:
what kind of control codes shall be issued?
what kind of timing ( and delays ) for how many milliseconds at which signals shall be performed
translation table of databits from databus to datawords at centronics plug.....)

That´s also the reason some interfaces don´t even have an EPROM....
that kind of interfaces just passes the databits directly to the port and the
timing is just determined by the delays of the hardware....
and the controller is nearly completely controlled by software...

In such a case you really need also the manual of the interface....
because if you don´t want to connect a printer, but instead control other hardware...
then you should have the manual and it is highly recommended to use a interface card
where the manufacturer listed in the manual the code of the EPROM
( some manufacturers did that at the rear end of the manual )
some of that interfaces had the option to be configuable by an amount of DIP switches ....
for example handshaking with "high"-bit or with "low"-bit....

and to change to modern terms: of corse you might "mistreat" such an interface as
"dialog-partner" with an external board, that has a MCU or PIC "on board" and pass over the
conversation with that device on parallel databus instead of using a serial port....

if you like to - you even can also do serial communications with use of only 4 or 5 bits of the parallel port...
it´s just fairly more slow than regular serial card and it´s dependent to the software you will write....
( but of course such games are restricted at those controllers without EPROM "on board"
or if Eprom is present it´s dependent to the contents of the EPROM....

and in such case of not connecting a printer it´s highly recommended to have
experienced knowledge in assembler programming....
then it would be possible to create a kind of "ampersand" low level software interface,
which may be used from Basic.... similar to use of ampersand techniques used by the Beagle Bros
in some of their software and explained in several publications at for example the nibble magazin....
just remember some of the famous publications out of "Garcia´s circuit cellar"

for example if you like to control a robotic arm or control a toy crane device or some other freak-usage...
the limits are only set by your mind...
the centronics interface protocol offers handshaking by use of the
acknowledge and ready lines....
speedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

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Re: Epson APL B printer interface

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