Hi Dilwyn, the bit about the EPROM slot being read-only is very interesting. The documentation in the technical guide and service manual are a bit vague around this subject but I didn't realize that the data lines on the connector would be one-way. The block diagram suggests that the slot's data lines would be one-way but the circuit diagram shows both the J1 and J2 slots' data lines directly connected to the CPU which would lead one to believe that the data lines would be two-way active on the ROM connector. My initial assumption was that a manner of memory mapped I/O would be possible through the slot.
If someone has any h/w designs lying around I would be happy to colllaborate and pitch in on the dreaded driver side of things. I can definitely see why the Qx0 platform is interesting to a wide audience but, bitten by the retrocomputing bug, I would love to implement something on the original hardware. Being a S/W engineer by profession I'm very much in the dark about the whole microelectronics side of things so I have no idea whether this whole project is at all feasible but it's an interesting subject, nonetheless :) Cheers, Petri On Sun, Sep 26, 2010 at 7:00 PM, Dilwyn Jones <[email protected]> wrote: > > ----- Original Message ----- From: "Petri Pellinen" <[email protected]> > To: "ql-users" <[email protected]> > Sent: Sunday, September 26, 2010 4:42 PM > Subject: [Ql-Users] Ethernet adapter for QL ? > > >> >> Hello, >> >> hopefully everybody is having a great weekend. >> >> Might be a FAQ, but... has anyone developed an ethernet adapter for >> the original QL either as a commercial product or a hobby project? I >> am studying if it would be feasible to use the EPROM slot and create a >> module with something like Microchip ENC28J60 Ethernet controller and >> a microcontroller e.g. the ATmega168 to interface with a device driver >> on the QL side. >> >> I have essentially zero experience in building any kind of hardware >> interfaces but I think it would be a great hobby :) >> >> Best regards, >> Petri > > If using the EPROM slot, you need to bear in mind that this slot is > read-only - it is designed just for EPROMs to plug in. > > That said, people like Miracle Systems (and others) have used it as a write > interface by using a special technique like a double read - the first read > is an address (to write to) and the second read puts data on the address > line somehow. I don't pretend to even half understand it, but I'm sure there > are others on this list with more knowledge of the QL hardware than me. > > Do bear in mind that some QL add-on interfaces like Trumpcard use pretty > much all available addressing space to provide more than the original design > limit of 640K RAM. > > I think Nasta (Zeljko Nastasic in Croatia) once proposed a QL ethernet > interface, and I think Peter Graf once suggested the possibilities of such > an interface for Q40/Q60. > > Dare I mention the dreaded word... "drivers" ? This is where so many > proposed hardware add-ons have fallen down over the years. > > Dilwyn Jones > > > _______________________________________________ > QL-Users Mailing List > http://www.q-v-d.demon.co.uk/smsqe.htm > _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
