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Post by eslapion on Mar 21, 2023 2:30:30 GMT
Is the Ki-CAD file available? My dream is to make something like the NEO 128 but with as many of these kind of modernizations as possible on board The VIC II now has and FPGA replacement, the SID has several versions that have paddle support. Ram is clearly done, we are really close to NEW C-128 that only need to be hooked up to programmer to function. I did the electronics design but not the PCB design so I couldn't give that even if I had it. Besides, this is not open source. Some people have installed 64k for the VDC on new C128 boards either by installing a Saruman-VDC under the VDC chip or by replacing the 2 DRAM ICs with a Saruman-64 (normally used on C64 boards 250469 and 250466). The Saruman-64 is less expensive.
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Post by eslapion on Oct 22, 2021 9:38:56 GMT
This product is available for sales NOW! I have 3 units in stock.
Pricing: 57$US (50 Euros) for the 2MB version, 90$US (77 Euros) for the 4MB version. Shipping to the US is 8$, to Europe is 8 Euros.
You must provide a CR2032 lithium battery to preserve the data when the power is off. It should last about 3 years.
The cartridge consumes 35mA whne under intense access (testing by GMT 0.44) which is about half the power of an original FastLoad cartridge so NO LARGER POWER SUPPLY REQUIRED!
Gold plated edge connector!
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Post by eslapion on Oct 20, 2021 10:31:20 GMT
The power consumption figures are interesting. When there is no access, the cartridge consumes 31mA and most of this is used by the XC9536XL - the same as a full intensity blue LED. With intense access on a standard C64 (testing with GMT 0.44) the power usage rises to 35mA - that's half the power of an original FastLoad cartridge. Intense access (testing with GMT 0.44) on the Ultimate 64 (set to 48MHz) causes the power usage to rise to 70mA - the same as an original FastLoad cartridge. robertb : Another PM is waiting for you on Melon64 !
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Post by eslapion on Oct 19, 2021 15:12:56 GMT
The 4MB version just passed all tests. Battery backup power has been measured at 5.75uA.
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Post by eslapion on Oct 19, 2021 3:12:46 GMT
The 2MB version just passed all tests.
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Post by eslapion on Oct 9, 2021 18:46:28 GMT
You are right in that GeoRAM has a default (fixed) page size of 16k.
The Ultimate-II has a GeoRAM emulation that can be set between 128k and 16M but in order for that to work beyond 4Mb, the behavior of the paging register was changed. ---
In a nutshell, GEOram is accessed via $DFFE (write only 0 to 255 16k block select) and $DFFF (block page 0 to 63 mapped to $DE00-$DEFF) The 4Mb is 256 times 16k blocks, each block of 64 pages of 256 bytes. 256 * 64 * 256 = 4194304
In a (modern, retro-)implementation you can decide to implement more than 16k per block, thus DFFE still selects up to 256 banks but these may be 32k and even 64k, allowing DFFF to select any page of that 64k from 0 to 255: 256banks * 256pages * 256bytes = 16Mb ---
Such page-size-behavior shall be configurable because if an application does not correctly map the page selection in DFFF (e.g. trashing bit6 and 7) then you'd get the wrong page. Note that if an application does that consistently then it (still) wouldn't matter (but the 16M GEOram would have holes in it). In other words, your implementation ideally must be able to disregard bits in DFFE (for smaller size) or DFFF (for 16k/32k/64k page)
I tested the CP/M bios with z64k and ultimate-ii.
Reading the wiki and other sites detailing the registers of GeoRAM, it seems to me you have inverted the function of $DFFE and $DFFF. See: codebase64.org/doku.php?id=base:georam_registersAt the moment, my GeoRAM clones called CleoRAM are bound by the limits of the XC9536XL which have no more than 34 I/O pins and 36 macrocells. They won't allow to control more than 4MB. Still, knowing I could eventually use a XC9572XL of 64 pins to get up to 16MB is quite interesting.
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Post by eslapion on Oct 8, 2021 3:44:51 GMT
AFAIK, the control registers of GeoRAM don't allow for more than 4MB so maybe you have information I could use. All these additional software are all motivation to make this thing work! To robertb : I sent you a PM on Melon64 to thank you for this additional information.
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Post by eslapion on Oct 2, 2021 1:44:13 GMT
AFAIK the original GeoRam from Berkeley Softworks was used only with GEOS. I am not aware of any other applications or games that can use a GeoRam. As such to use it with GEOS64 or GEOS128 you will need a new Config file and to take advantage of the battery battery backup you also need a new Re-Boot file. For the C128 there is an updated GEOS128 here. commodore.software/downloads/download/823-c128-operating-systems/15755-geos-128-v2-0r-update. This GeoRam and the GEOS128 update could make a nice set-up for anyone who is a heavy GEOS user. Things have evolved considerably. The battery backup was requested by a number of people and I honestly did not bother to verify anything on the software side that may be required to take advantage of it. I know NeoRAM Remix has it. This is all software that can take advantage of GeoRAM or larger versions of it. members.optusnet.com.au/spacetaxi64/CBM-REU-TOOLS/GEORAM-TOOLS.htmThese are all games that can take advantage of a GeoRAM of various capacities. members.optusnet.com.au/spacetaxi64/CBM-REU-GAMES/GEORAM-GAMES.htmHowever, very few software can take advantage of a 4MB GeoRAM and one of them is GEOS MP3. Me, I'm just the hardware guy. I was told "build it and they will come" and so I do.
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Post by eslapion on Sept 23, 2021 12:46:27 GMT
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Post by eslapion on Sept 5, 2021 16:31:44 GMT
I am the author/perpetrator of that particular memory expansion. ... The heaviest hit power-wise is the second MMU. (150mA, max.) I made sure to use CMOS DRAMs for the added RAM, and only four of them, as 64Kx4s. I optimistically (or naively,) assumed that the PSUs for both the low profile '128 and '128D had sufficient current capacity. I never experienced any power problems. ... Since a Saruman-128 replaces all 16 4164 DRAM of a C128 and consumes about 10mA of power (on the 5Vdc) I suspect using four Saruman-128 would provide the 512k of your memory expansion AND result in lower power consumption at the same time. I would gladly send you 4 samples of that module if you were to publish a building manual that uses these instead of DRAM.
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