68kMLA Classic Interface
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| ProtoCache1 - IIsi/SE/30 PowerCache Adapter Prototype Development | |
Posted by: joethezombie on 2017-10-02 10:00:42Just held it up against the open SE as if it were in the vertical passthru of my multi-slot AI models. It fits! [ 😀 ] FANTASTIC! Woo-hoo! | |
| Posted by: Bolle on 2017-10-02 14:43:18 I will chop off the +5V plane around the Cache connector and implement jumpers that let one connect it to the rest of the VCC plane. If you chose to get your 5V for the accelerator from somewhere else you can plug in a floppy power plug which is connected to the 5V plane around the cache connector. That way one can decide to run the accelerator from power supplied by the host PDS slot or an auxiliary power supply. The extra card on the passthrough as well as the MacCon sitting on the bottom will be powered from the host PDS slot. If you leave out the additional card on top and only run MacCon+accelerator there is no need for extra power and you can set the jumpers to connect both VCC sections. That's KISS right there if you ask me 😉  | |
| Posted by: joethezombie on 2017-10-02 15:05:34 It’s beautiful! *wipes tear from eye* | |
| Posted by: joethezombie on 2017-10-02 17:47:15 Here's a scan of one of my Xceed cards with a measuring stick for reference. Not metric, sorry:  Here's the low-profile HDD mounting "plate" I intend to use, with SCSI2SD mounted on top for that ultimate in anorexic getup:  | |
| Posted by: K55 on 2017-10-02 19:26:02 Going to whip up something quick for power. 1 sec. | |
| Posted by: K55 on 2017-10-02 19:56:11 Nevermind saw bolles post 🙁 | |
| Posted by: Trash80toHP_Mini on 2017-10-02 20:26:50 Sweet, thanks. NoPro on the inches. A 3" tank or anti-tank gun is 76.2mm, so your six inch ruler will be twice that for pretty easy scaling. Number associations can be very, very strange things. :🙂 Bolle, have you looked at the mounting ear complications for your layout? I'll get your layout into Illustrator. In the meantime, print it out, paste it up to cardboard and lay that with your wrong angled NIC on top of your GS Card to determine the points of interference. Looks like you need to convert the mounting holes for your bottom slot connector to the RA connector configuration mirroring your female passthru connector provisions on top? I wouldn't use headers for power connections, pretty sure they're not reliable enough anyway. I'd add thruholes for soldering nice fat copper jumper wires if anyone wants to overtax PDS Power spec by running more than two cards. Normally I'd say put butterfly traces on outer layer in your layout to be easily cut when adding aux power. But in this case I'd leave both options "open" for a user to make a conscious decision as to which route to take at their own risk. KISS is good CYA is better. [😀] ]'> | |
| Posted by: joethezombie on 2017-10-02 20:46:25 Hey K55, if you have an idea, throw it out here. We're in the primordial soup phase! | |
Posted by: Bolle on 2017-10-03 04:53:41*snip*Those are: R1 1,2kohm pull up /BGACK R2 390ohm pull up /RESET R3 680ohm pull up /BERR R4 680ohm pull up /HALT R5 1,2kohm pull down CPUDIS Correct? Numbers in your picture are a bit hard on the eye. | |
| Posted by: joethezombie on 2017-10-03 07:08:53 Values verified, Bolle! | |
| Posted by: MJ313 on 2017-10-03 07:39:36 You guys kick ass. Awesome job joe, jt and everyone else working on this! | |
| Posted by: Trash80toHP_Mini on 2017-10-03 13:15:44 THX, mj, your support and that of others all along has been a great help. IRQ 1/SLOT $9 = available on SE/30 PDS IRQ 2/SLOT $A = available on SE/30 PDS IRQ 3/SLOT $B = available on SE/30 PDS Holy crap! Just went back to confirm that three slot interrupt/Slot ID availability on the PDS and realized this will very soon have been a three year roller coaster ride! 8-o | |
| Posted by: joethezombie on 2017-10-04 20:22:59 Added the capacitors and worked out the CACHE signal. Note the added pull-down and detached state of the CACHE signal across the THRU slots. The original card has additional capacitors located at the FPU socket, which I have omitted.  EDIT: Next steps- 1. Triple-blind-check and make sure everything is in order. For this, I will remove all the components from the board so I get no interaction from resistors or capacitors while I noodle it all out. 2. Try the adapter with a dual PDS riser and see if I can truly run two PDS cards and a PowerCache without issue. 3. Design the cards. Bolle has done a damn fine job on the PowerPerch™ adapter. I have a few ideas for my TripleNipple™, and I know jt has some great things coming as well. | |
| Posted by: K55 on 2017-10-05 09:36:13 You'll probably want to decouple all of the power lines at least once and put a big decoupling cap near each 5v line near the 3 sockets. Thats around 7 or so caps, which you can clearly see on the twinspark 😉 . | |
| Posted by: Trash80toHP_Mini on 2017-10-05 10:07:21 Great input! I'm still fumbling about with the two TTL input driving restriction specification for the PDS. Overloading the spec by 50% for adding another passthru is one thing, but expecting the PDS to handle inputs for three passthru slots seems more than a bit excessive. Been looking for a TTL driver chip but was wondering: -- am I looking at this from the wrong direction? -- should I be looking at the input driving capacty of the PowerCache? -- It's the accelerator that will be driving the inputs of the expansion cards, no? -- have we got any spec on the input driving limitations of the PowerCache? -- might this be problematic? I'm now wondering if TTL drivers might be needed for the PowerCache's output lines as opposed to those of the PDS? | |
| Posted by: joethezombie on 2017-10-05 10:50:13 DCaDftMF states signal buffering should occur on the expansion card, so i’m operating on the assumption that the cards were designed that way. But I am curious, what three PDS cards would you attempt to install? Video and Ethernet are a given, but what else even exists? | |
| Posted by: Bolle on 2017-10-05 11:00:03 Another ethernet card for routing capabilities or another video card for multi-monitor setups 😛 Those IIsi pivot cards are pretty small, there would fit a lot of those in there. I was going to add some more caps than the ones that are needed near the slots anyways. I also have been looking at line drivers that might be suitable. What lines should be send through those? Adress and data bus only or all other signals as well? We will need a lot of buffers if we want to run all signals through one. Edit: Regarding the whole two cards + accelerator issue. Gamba did run grayscale, ethernet and powercache back in the day I think. It just did not fit inside the case with the adapters and wrong-angle wizzardry they had to go through. | |
Posted by: Trash80toHP_Mini on 2017-10-06 10:47:53But I am curious, what three PDS cards would you attempt to install? Video and Ethernet are a given, but what else even exists?/monthly_01_2017/post-902-0-92719400-1485897653.jpg">View attachment 11540 😛h34r: | |
| Posted by: joethezombie on 2017-10-06 22:34:56 NuBus? Oh boy... | |
| Posted by: Trash80toHP_Mini on 2017-10-07 16:29:35 NuBus! Heh! [😀] ]'> A man's gotta have an impossible dream! This windmill has been rocked to its foundations and that rubble is soon to be blown away after a three year campaign. Time for bashing my head on another one that's been in the works for a while . . . about five years on and off. :🙂 | |
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