Tinkering with a 68hc000 in an A500

[Yulquen74]

E-Penguin: I have removed all RAM in A590 as it would make no sense to have it
installed, as it would fragment the RAM further, the A590 RAM needs to follow
mainboard speed, and that RAM area is already covered on my board.

I do not sell them as I only made a few (which are all in use), and in the process
Renesas, the manufacturer of the 8MB SRAM chips I use, decided to stop
making the 70ns chip I was using (which I got for around 10 euros) and only
deliver the 55ns version of the same chip, which costs like 60 euros a piece (2 are needed).

Besides, selling an accelerator requires you to have a more mature product,
with I believe mc68k and others achieved much better in their projects.

[PR77]

Originally Posted by Yulquen74

I have created a small tool in assembly which I can use to control clock frequency and fastrom stuff, I run it during boot as shown in the video, I also show its help text in the video.

The way I use it, I copy the kickstart to 0xe00000 RAM.

Do you know if a tool exists which only copies a KS file (or any arbitary file for that matter) to a defined memory address?

As my 68SEC000 accelerator is now working I would like to play with a MapROM / SPIROM strategy.

[Yulquen74]

No, but I have not looked for such either.

Though I could send you the source of my control program if you could pluck out some useful parts of it (its written in DevPac, and heavily commented).

[PR77]

Originally Posted by Yulquen74

No, but I have not looked for such either.

Though I could send you the source of my control program if you could pluck out some useful parts of it (its written in DevPac, and heavily commented).

That would be great! Are you happy to PM to me? Full credit will be given to whatever I use.

FYI., my Accelerator is GPL 3.0 and is published in GitHub (user PR77). Although it is a bit out of date, been to busy to publish the details for the latest revision but I will get around to doing that. So whatever I do will end up being Open Source.

[mc68k]

Meanwhile I have released a successor of the HC508: it is called Classic 520

http://irixlabs.com/c520

-68EC020 CPU running at 28 MHz (~10x A500 speed)
-40 pin IDE connector for HDD, CD ROM etc.
-Integrated CF card connector (bootable)
-Integrated SD card connector (FAT 16 / FAT32 compatibility for fast data exchange, hot swap)
-8 MB Fast RAM
-512k FlashROM for Kickstart image
-Bootmenu for controlling the system functions
-Amiga 500 and Amiga 1000 compatibility
-Better WHDLoad compatibility due to 68EC020 and VBR

[Jope]

Nice one!

Still dreaming of that 1.5MB C00000 RAM, I think it would be a good addition to an already great product range.

[Yulquen74]

I did have another go at the CPLD setup on my 68HC000 accelerator to exploit/add some more
fast-ram in the 24 bit range, just for the fun of it.

Now I can add everything that is not used by the Amiga hardware, heck even the primary
autoconfig space at 0xe80000 can be added as fast-ram during boot, as long as it disappears
when reset, and the A590 DMA's fine into it.

So, with everything enabled, I have the following fast-ram ranges:

0x200000 - 0xBFCFFF 10.228 KB
0xC00000 - 0xDBFFFF 1.792 KB
0xDC1000 - 0xDFEFFF 248 KB
0xE00000 - 0xE8FFFF 576 KB
0xEA0000 - 0xF7FFFF 896 KB
Total amount of fast-ram: 13.740 KB / 13.4 MB

If I have only 1MB chip-ram, I can have an additional MB of fast-ram by extending the 0x200000
range downwards (its of course disabled at reset).

When booting OS3.2 and some commodities like MultiCx and such, the memory meter
reads 12.253.296 free bytes of fast-ram.

[PR77]

Cool update!

[AmigaHope]

That's a lot of RAM for a 24-bit A500! Impressive. I assume the smaller blocks are given highest priority in the memory list so they get allocated first (to reduce fragmenting the big blocks)?

[Yulquen74]

AmigaHope: Yes correct, thats how I do it. Those smaller blocks are filled during boot
with libraries and other os components, and the larger blocks are not used unless required.

As an example of a program needing much memory, the PFS doctor consumes >11MB fast-ram (not one continous block though) when checking my 33GB entertainment partition, which leaves only around 900KB of free fast-ram while it is running.