Jim Manley wrote:
Pithagoros wrote:Personally I think that the lack of a parallel port is the biggest mistake with the Pi Zer0 design, without a centronics interface, how am I supposed to drive my daisywheels and band printers?
Oh, and it's also going to be a right royal pain to get the Zer0 onto my token ring network.
And I was hoping to reuse my 16K ZX81 Ram Pack, looks like that's a non-starter too.
All in all it looks like it's going to be a disappointing Christmas this year.
OMG, I'm LMFAO, and now I can't stop crying! That is the FUNNIEST thing I have seen here in ... forever!
Firstly, this is my first post on this forum... <Gulp>
Secondly, I fully recognize that I'm replaying to a somewhat OLD (deceased?) post... I only FOUND this old post while I was 'searching' through the forum for 'Centronics'.
Nevertheless, _some_ of you might find the following mildly amusing...
I'm NOT trying to interface my old Star dot-matrix parallel printers. In fact my primary purpose for the Pi is to actually get RID of them!
The (ancient!) PC in question talks to 3 separate parallel printers and it's getting difficult to maintain them. I cannot easily just upgrade the PC and printers because there's a pair of HIGHLY custom 8-bit ISA cards that are the whole purpose. (Wait for it... They're built using wire-wrap technology!).
Furthermore, the PC isn't Microsoft-WIndows or even some version of MSDOS. It's Concurrent DOS (a forerunner of DRDOS)
What I'm intending is to allow an RPI to totally 'replace' the physical parallel printer. Any parallel data 'print'-ed to it can then be displayed on screen, sent out to some device on the LAN, or even sent out to a USB-attached printer.
Reading the Centronics input would be pretty easy using an Arduino (eg: Mega), but it's not so easy to hook a screen or LAN to it as it is with an RPI!
However, reading the Centronics input on an RPI isn't exactly childs play. Admittedly, the actually connectivity to GPIO pins is easy enough via a pair of 74LVC4245 level shifters to handle the 5V<->3V3 difference. My main concern is that the Centronics strobe pulse can be as short as 0.5uS. Also, I want the port to be as FAST as possible so I want to alleviate the bulk of the interrupt latency issues I'd encounter. In other words, I'm considering rolling my own 'centronics-device' kernel module.
Anybody that's not ROFL by this point must be almost as insane as I am!
Perhaps the most hilarious (insane?) aspect is that I was actually searching here to see if anyone had already done something like this...
Perhaps it's time for me to dig out my Signetics 2650 box to see if it can be networked to my Altair 8800? (It was too hard using the 4-bit 4004 due to the higher VCC rail. Or perhaps it's just that my 4001 programmer isn't working properly?)