Re: [ql-users] QL Schematic
On Sat, 5 Jan 2002 at 22:24:17, P Witte wrote: (ref: 000e01c19637$d1395e10$0100a8c0@gamma) If were thinking about a future for the QL in line with its promising beginnings something entirely different is called for than trying to catch up with mainstream. The QL isnt a PC; its a computer! We can only move ahead if we make the QL do things other systems cant do, and/or make it more interesting. The idea of the Ibox, an matchbox sized 'embedded' type of QL, mooted by T (8-)# F some years ago was a good idea in the first category - why did it go away? Stuart H lost interest, and I got this lucrative programming job. I simply do not have the time to think about anything really complex (and expensive to develop) as this. -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
Re: [ql-users] QL Schematic
On 1/4/02 at 4:22 PM Dexter wrote: I'm still looking for a schematic of the QL PCB. Also, the 8049 details. Actually, you do not need the 8049. All it does can be done using a different device and handling the difference on the software side (translation: modified OS code). I'm thinking of prototyping a 680X0 board with the basic QL facilities, minus the dodgy serial and net ports, plus IDE. I have a strongarm design here which has USB and ethernet and I'm seeing if there's a way to take advantage of any of that knowledge. A quick question: what do you use for USB? Also, the +5v is obvious, but if you ignore the net, serial and microdrive interfaces, was the +/-12v used anywhere else? Only as a bug fix for the 8302 ULA which incorporates the 9049 IPC interface, microdrive logic, reset, half the serial ports and the network, all of which you can forget - except for the RTC. The later is a simple 32 bit second sounter. If you don't use a 8302, then you don't need +-12V. Serial port levels can easily be handled by something like a MAX232 or it's many successors and clones. Finally, on some QLs there was a variable capacitor (?) mid-board. What did it do? How was it set? It disappeared on later revision boards. It was used in the RTC oscillator (32768Hz crystal plus a few other components). The purpose of the variable cap was to adjust the exact frequency. However, the osc. circuit used in the ULA does not lend itself to precision, and the select logic for the 8302 has a bug which more often than not corrupts the RTC register when power is applied. With later board revisions, any pretense at battery back-up for the RTC internal to the 8302 was abandoned, and with it the need for the RTC to be very precise - it was enough that the drift was not too bad within a single session (between two power-ups). Later, the GC and SGC boards introduced their own RTC which operates by loading the contents of the local RTC into the 8302 RTC, where it can then be compatibly read. I am really very intrigued at what you propose to design - especially since I am myself involved in an (ever ongoing!) process of designing a QL board to replace the GC/SGC. Even so, it seems there is a real need for something that would be a true replacement of a SGC, rather than it's successor, something like a SGC II. The demise of the SGC is connected to an Altera EP18010 being used for all theglue logic, a chip which has long ago been obsoleted. The FDC controller on the SGC is also not available any more, but it has a fully compatible replacement (made by SMSC). Also, the current state of affairs with memory, would make a potential 68EC020 based board for the QL very tiny - 16M of RAM could easily be squeezed into two SDRAM chips - and that only because 16-bit wide ones are easyer to get then the 32-bit wide ones. Something along these lines would make a great QL based SBC. Not one to contend for the fastest QL out there, but it should be very practical. Nasta
Re: [ql-users] QL Schematic
On 1/4/02 at 9:55 PM Dexter wrote: On Fri, 4 Jan 2002, ZN wrote: A quick question: what do you use for USB? [Microchip] ...I thought so. I've looked at the USB97C100 (not directly in connection with QL hardware, though) and like most implementations, getting one's hands on a non-PC speciffic controller proved to be impossible once again. Altera EP18010... a chip which has long ago been obsoleted. I'm assuming this is a ULA/FPGA. If so, is the logic it represented available anywhere? The Q40/60 use FPGAs, so we definitely have the skills to prepare a new part within the community... Please make the appropriate distinction between a CPLD and a FPGA (although either moniker hardly describes the devices commonly found in either group... but that's a semantics discussion). The EP1810 is a (for today's notions) relatively low density CPLD, however, one that has some rather unusual characteristics. The logic in it is sort-of' available, if we manage to ever decipher it's original designer's files :-) but even so, it would really need a redesign as most today's CPLDs have a different organization, for which using the logic hand-optimized for the EP1810 would just be an impediment. (Sidebar:- Why did you use four FPGAs on ther Q40/60? Was it more cost effective, and/or were the devices representing functional blocks that you wanted to keep separate?) I'm not Peter, but I think I can answer that: the best ratio between function and price. I'm going to be using one large CPLD on the GoldFire simply because of space constraints. And to answer another of your questions: I have uploaded all the Aurora files (schematics and sources to the three CPLDs) as well as a lot of other stuff about Qubide, and the GoldFire, into the files area in the QLhardware egroup. Some of the GoldFire stuff is obsolete, specs have changed but not looking from the standpoint of the functions available. Anyone can read this, but only members can upload. I understand many people have (justified) qualms about joining egroups. The best way I have found to do this is to get one of the many free email accounts, and promptly forget it. Use it only to sign onto egroups, then set your group to 'no email'. You can check the messages on-line, it's not like the group produces many messages, so no bandwidth problems there. The 'forgotten' email address will serve as a spam catcher. I could easily transfer these elsewhere, but at least Egroups alow relatively easy administration... If I were to go out on a limb, I would specify: Capacity: 68060 - at 50MHz or better 4MB flash ROM - for QDOS, SMSQ/E etc, plus room to grow. 32MB RAM - expandable by daughter card[1] Interfaces: Monitor - SVGA, XGA capable IDE - ATA if possible Ethernet - 10/100 if possible[2] Serial - up to 115k Parallel Sound - line in, line out, mic GPA - General Purpose Adaptor[3] [1] Daughter cards or use SIMMs/SDRAM and throw half the capacity away may be cheaper... [2] I think this is essential... [3] This would be to this board what the expansion port was to QL classic. OS: This is much more vague, because it isn't my area, but I'd be looking for modularisation of the OS. Ok, not to demean any of your other comments, I'll get to them in a later email (hopefully :-) ). If you go for the above, you will be creating the third system along these lines. The first one is obviously the Q60, the second - still largely paperware except for the chips sitting in my drawer here - is the GoldFire. The Q60 does not have integrated ethernet and IO, the Goldfire does not have integrated graphics and IDE (and is intended to work as a 2 or 3 board system using either old QL peripherals or new, yet to be designed replacements). It also has only 10BaseT ethernet, but that could easily be upgraded to 10/100 using the same SMSC chip as used on the 5307 Toast board. BTW I wonder where they got the neat sockets with integrated magnetics, I've been looking for those for ages!
Re: [ql-users] QL Schematic
On Fri, 4 Jan 2002 at 16:22:58, Dexter wrote: (ref: [EMAIL PROTECTED]) Hi all, I've had at least half a dozen offers for machines by private email. Thank you! I'll reply individually tonight... I'm still looking for a schematic of the QL PCB. See my homepage - Overseas price list. Also, the 8049 details. More difficult - ask Laurence Reeves - lausATlausDOTdemonDOTcoDOTuk I'm thinking of prototyping a 680X0 board with the basic QL facilities, minus the dodgy serial and net ports, plus IDE. I have a strongarm design here which has USB and ethernet and I'm seeing if there's a way to take advantage of any of that knowledge. I'm not looking to manufacture anything, but if I come up with any *good* interface schematics I'll publish them. Also, the +5v is obvious, but if you ignore the net, serial and microdrive interfaces, was the +/-12v used anywhere else? No - but it was not used for the network. It was also connected (via resistors) to the two mdv data lines. Finally, on some QLs there was a variable capacitor (?) mid-board. What did it do? How was it set? It disappeared on later revision boards. Issue 5 - it was to trim the real time clock -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
