Getting a Centronics printer interface up and running

[drpeter]

14 hours ago, TGB1718 said:

I fact you can run it with just STROBE and BUSY if you wait for BUSY after STROBE is sent.

Which is what the AT Graphix does- it has no ACK line connection

[ClausB]

16 hours ago, TGB1718 said:

The 72000 device I have uses a 8035 CPU which has internal ROM and RAM, in spite of that it still

uses and external ROM chip.

Officially the 8035 was a ROMless 8048 but it might have been really an 8048 with defective mask ROM. Either way it was meant to be used only with external ROM.

Edited August 28 by ClausB

[+MrFish]

More information about the Xetec Graphix AT devices.

 

I noticed the (purple cover) 1987-version interface documentation calls the device a "Graphix AT+" throughout. I also thought I had seen some devices before being sold as "Graphix AT+". Turns out, there is a device which has a manual labeled "Graphix AT+" on the cover; although the corresponding device that comes with it is still just labeled Graphix AT (as all the devices are) -- but with the same label as the original "Graphix AT" device (tan colored), and a similarly-styled manual as the original device. The manual for this other device is also copyrighted 1987, and the device itself has the DIP switches on the right side, like the later device version with the purple label. So, it most likely also has the single-chip design. It also specifies having NLQ capability on the manual cover.

 

Basically, what it comes down to is the following.

 

1. Graphix AT device (tan color label) and manual (tan color cover). No NLQ capability [multiple-chip design].

2. Graphix AT+ device (tan color label) and manual (tan color cover), with older "Graphix AT" label on device, but labeled "Graphix AT+" on the manual cover, and called "Graphix AT+" throughout the manual. Manual specifies NLQ capable. [most likely single-chip design]

3. Graphix AT+ device (purple color) and manual (purple color); the new label, device, cover, and copyright page call it "Graphix AT", but it's referred to as "Graphix AT+" throughout the manual. Manual specifies NLQ capable. [single-chip design]

 

So, it looks like there are just two basic devices (items #2 & #3 above assumed to be the same), but with some differences in labels and naming on the manual cover and copyright page for the NLQ, single-chip design devices.

 

This is generally documented on my website (including a copy of the 3rd manual): Hardware Computerist - Xetec Graphix AT -- but I don't picture any of the devices there (yet).

[Note: You may need to refresh (<F5> or <ctrl><F5>) in order to see the updated site pages.]

 

Ebay: Xetec Graphix AT+

 

 

 

 

 

[Edit: One incomplete description corrected.]