🚀 go-pugleaf

In article <1989Sep5.162247.23447@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>In article <1078@rex.cs.tulane.edu> hoang@rex.UUCP (Dzung Hoang) writes:
>>    I just bought a used Microfazer printer buffer by Quadram.  The seller
>>said it has a capacity of 64K, but when I opened buffer, I found 16 64K
>>RAM chips, indicating 128K...
>
>That probably means 64KB of data buffering, plus working space for the
>processor.  (I'm surprised that it would need another 64K, but it definitely
>will need some, over and above the rated capacity.)

Unless, of course, it uses a microcontroller with on-chip RAM and
mask-programmed ROM (like the 8048, which it does).

I got mine used, with no docs, from a computer surplus place.

It seems to print its memory size on the connected printer if you
hold down the pause/copy button when you reset the Quadram box.  Reset
again to stop print.

Operation seems to be pretty straightforward.  Plug it in to your
printer and your computer.  Mine has a switch to select between an
external "wall-wart" supply (9VAC, 500ma), or supply from printer
connection.  (Unless you've got a heavy-duty supply in your printer
with lots of spare capacity, use the external supply.)

When your printer is on-line and ready, the "Error" light on the
buffer should be off, and the "Ready" and "Copy" lights on.  (The
"Error" light on the front panel displays the status of the printer's
"Error" line (paper out, ribbon out, etc.)).  At this point, you can
send data to the printer.  If the job fits within the buffer, the
"Copy" light remains lit and pressing the Pause/Copy switch will cause
additional copies to be printed without your having to re-send the
job.  The "Copy" light will extinguish if the Quadram's memory fills
up, indicating that there wasn't room for the whole job.

The "Ready" light indicates the status of that line as seen by the
computer.  

The "Reset" switch may be used to abort printing a job in progress and
to clear the Quadram's memory.

I believe the device is self-configuring; just plug in more memory and
it should find it.  (A standard memory-sizing trick is to read the
byte at the top of each "page" of [potential] RAM, alter it, write it
back, read it again and compare.  If the program succeeds in changing
the value, there's RAM there.  If not, you've found the top of RAM at
the previous page.)

The empty socket is, I believe, for an external program EPROM,
probably used for testing during manufacturing, since the on-chip
program ROM is limited to, I think, 2K bytes.

Greg Wageman			DOMAIN: greg@sj.ate.slb.com
Schlumberger Technologies	UUCP:   {uunet,decwrl,amdahl}!sjsca4!greg
1601 Technology Drive		BIX:    gwage
San Jose, CA 95110-1397		CIS:    74016,352
(408) 437-5198			GEnie:  G.WAGEMAN
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Opinions expressed herein are solely the responsibility of the author.