I have had two other requests for a 16MB address range, so I will add A22,A23.
I am concerned that placing them on the pins you suggest could create unnecessary difficulties for 2-layer designs. I will look at options and take further suggestions before making a revision. Thanks for your input :) Dave On Tue, Jan 14, 2014 at 7:00 AM, Malcolm Lear <malc...@essex.ac.uk> wrote: > Hi Dave, > Nice idea. I feel that it would be diligent to go for at least 4 more > address lines (I need at least 16 mb with QPC). With that in mind it might > be good to place them to match the new extended data lines ie A20 - 23 on > pins C15 - C18. > Cheers, > Malcolm > > > > On 14/01/2014 11:45, Dave Park wrote: > >> A proposal for an extension of the J1 expansion connector to three rows. >> The intent is for it to be backwards compatible with all traditional >> 64-pin >> expansion cards. >> >> The purpose of the 96-pin expansion connector is: >> * to increase address and data space for 32-bit CPUs by adding D8-D31 and >> A20,A21 >> * improve grounding >> * to release some pins that were never used in any expansion: RED, GREEN, >> BLUE, VSYNC and CSYNC >> * to retain full backwards compatibility >> >> The version number of this proposal is currently V0.1 >> >> DISCLAIMER: >> >> This proposal is based on my experience with 68008, 68000 and 68020 CPUs. >> Other CPUs may take advantage of different features. If you're aware of >> changes that would facilitate the widest range of CPUs, please let me >> know. >> >> DISCUSSION: >> >> The QL Forum (http://www.qlforum.co.uk/viewtopic.php?f=2&t=729) will be >> used for a consultation period lasting until February 28th 2014. After >> that, the resulting expansion will be considered defined. The standard >> will >> be under continual review, but any changes will be backwards compatible to >> ensure interoperability. All future expansions can optionally use the >> traditional DIN41612 2-row connector, or the expanded 3-row connector. >> This >> will be an open standard. If any party intends to make a motherboard or >> expansion that uses the new standard, they can use it royalty free and >> without obtaining consent. I, Dave Park, will maintain the standard, and >> will take requests for designation of available pins by mounting a >> discussion like this one, then adopting and revising the standard. Any >> reasonable proposal can be adopted after a 14 day consultation period in a >> public forum. >> >> Video: >> To my knowledge, the RED, GREEN, BLUE, VSYNC and HSYNC pins were never >> used >> on any mass-produced expansion. Because of their purpose, expansion cards >> neither tied these to ground or connected them in any way. Further, these >> lines introduce a lot of noise across the board. It is proposed to >> deprecate these tags, and to make a12 "A19" and b13 "A20" - thereby >> expanding the address range. If anyone knows of any reasonable objection, >> or benefit to address lines beyond A21 (4MB), please discuss below. >> >> Additional lines: >> Adding row C allows 32 extra pins. This allows the extension of DATA lines >> to encompass 32-bit CPUs. It also allows the expansion of the 68008's >> combined IPL0/2 to two separate lines, IPL0 and IPL2. >> >> Two pairs of ground pins are provided in row c. This serves a dual >> purpose: >> the primary purpose is to allow improved grounding to expansions. The >> secondary purpose is that, by the addition of two jumpers, it is possible >> to prevent accidental wrong insertion of a 2-row card in a 3-row socket in >> the -BC position. >> >> The provisional revised expansion connector is listed at >> http://www.qlforum.co.uk/viewtopic.php?f=2&t=729 Changes are highlighted >> in green. Changes that generate ongoing discussion will be changed to >> yellow, and changes that create controversy will be highlighted in red. >> >> If you do not wish to join the QL Forum, discussion here will be reflected >> in the standard also. >> >> > _______________________________________________ > QL-Users Mailing List > http://www.q-v-d.demon.co.uk/smsqe.htm > -- Dave Park Sandy Electronics, LLC d...@sinclairql.com _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
