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Author Topic: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?  (Read 6445 times)

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Offline Blizzard 128 MBTopic starter

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Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« on: October 30, 2015, 11:27:39 PM »
Hello.
Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM (trapdoor slot) possible? How?
I expanded an Amiga 500 rev. 6A 0,5 MB motherboard to 1 MB chipRAM with 8375 318069-16 Agnus (PAL system, max. 1 MB chipRAM). Original Agnus 8371 (max. 0,5 MB chipRAM).
http://s2.postimg.org/8o0x83w69/A500_6a_1_MBCHIP.png
My motherboard: http://amiga.resource.cx/photos/photos/a500rev6a-2.jpg
« Last Edit: October 30, 2015, 11:31:06 PM by Blizzard 128 MB »
 

Offline Greyspirit

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Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #1 on: November 10, 2015, 04:38:45 PM »
can get 8mb + CF with Kipper2k board. Works with my 512K expansion in trap door on 6A board. I had to get the $5 adapter kit too. Also ended up ordering kickstart 3.1 rom from somewhere else so I can can use the CF card without a boot floppy. Luckily I still had my old 3x floppies.
 

Offline psxphill

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #2 on: November 10, 2015, 07:12:10 PM »
Quote from: Blizzard 128 MB;798493
Hello.
Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM (trapdoor slot) possible? How?

I believe one of the 2mb megachip boards allowed this, because it came with 2mb of chip ram. You didn't jumper gary differently, so the c00000 memory stayed where it was. Instead there was a wire that attached to gary and the megachip board dealt with the addressing.

But it's been many years since I had such a modified a500. IIRC I had 2mb chip + 1.5mb trapdoor.
 

Offline Motormouth

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #3 on: November 11, 2015, 04:45:12 AM »
Quote from: Blizzard 128 MB;798493
Hello.
Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM (trapdoor slot) possible? How?
I expanded an Amiga 500 rev. 6A 0,5 MB motherboard to 1 MB chipRAM with 8375 318069-16 Agnus (PAL system, max. 1 MB chipRAM). Original Agnus 8371 (max. 0,5 MB chipRAM).
http://s2.postimg.org/8o0x83w69/A500_6a_1_MBCHIP.png
My motherboard: http://amiga.resource.cx/photos/photos/a500rev6a-2.jpg


That is a good question.  I don't know the answer.  It would be interesting to put an A501 or clone on your system to find out.  One problem would be is this "fast" ram would be slow.  As far a address space I think up to 1.8 megs of slow ram is "possible" on an amiga but would require some level of hacking or gary jumpering.  

further I agree with Greyspirit true fast ram will be faster than trapdoor slow ram.
Or get an edge connector ram card of some sort with true "fast" ram.
 

Offline Blizzard 128 MBTopic starter

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Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #4 on: November 11, 2015, 05:30:27 PM »
I saw all of the expansion here:
http://www.bigbookofamigahardware.com/bboah/CategoryList.aspx?id=28
A Gary adaptor and wire+GAL is needed for the all 1,5, 2, 4 MB trapdoor fastRAM expansion card.

Rev. 6 motherboard 1 MB chipRAM (1 MB Agnus) + 0,5 or 1 MB fastRAM possible with trapdoor card, but how?
A500+ rev. 8 motherboard with 2 MB Agnus = 2 MB chipRAM simple. 1 MB chipRAM on motherboard + 1 MB expansion card.
I use in 2010  a rev. 6 motherboard (0,5 MB chipRAM) machine + a 1 MB expansion card.
The result: 0,5 MB chipRAM and 0,5 MB fastRAM.
A500+ rev. 8 motherboard 1 MB chipRAM + 0,5 or 1 MB fastRAM how possible with trapdoor card?
The same may be the solution both motherboards.

1 MB chipRAM + 2 or 4 MB fastRAM possible with rev. 6, or rev. 8 motherboards?
Or 0,5 MB chipRAM + 2 or 4 MB fastRAM possible only with trapdoor card?
Example:
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1067
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1015

I connected the 0,5 MB fastRAM card to the trapdoor slot (1 MB chipRAM rev 6 motherboard), the fastRAM not exist.
The J7A jumper cut (0,5 to 1 MB operation) = trapdoor slot off.
I restored the J7A jumper to the original state, but the machine did not work.
I cut J7A, A500 work. The Gary wire necessary.
Without Gary wire 1 MB chipRAM + 0 MB fastRAM, or 0,5 MB chipRAM + 0,5 MB fastRAM possible only.

I  do not want to buy a RAM expansion card, or rev. 8 motherboard. I want  to use my rev. 6  1 MB chipRAM motherboard + 0,5 MB fastRAM only.
There may not be big disadvantage, if I expand the motherboard onto 1 MB.
 

Offline Oldsmobile_Mike

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #5 on: November 11, 2015, 06:56:22 PM »
Quote from: Blizzard 128 MB;799094
I  do not want to buy a RAM expansion card, or rev. 8 motherboard. I want  to use my rev. 6  1 MB chipRAM motherboard + 0,5 MB fastRAM only.

Why are you making this so hard on yourself?  If you want to add more memory internally why not just buy one of these?  4MB + IDE support for $64 USD.  Or 8MB for the princely sum of $74 USD.  Since it connects directly to the processor this will be real fast ram (like through the side expansion slot), not that fake "slow-fast" ram.  But it's your Miggy, do what you want.
Amiga 500: 2MB Chip|16MB Fast|30MHz 68030+68882|3.9|Indivision ECS|GVP A500HD+|Mechware card reader + 8GB CF|Cocolino|SCSI DVD-RAM
Amiga 2000: 2MB Chip|136MB Fast|50MHz 68060|3.9|Indivision ECS + GVP Spectrum|Mechware card reader + 8GB CF|AD516|X-Surf 100|RapidRoad|Cocolino|SCSI CD-RW
 Amiga videos and other misc. stuff at https://www.youtube.com/CompTechMike/videos
 

Offline psxphill

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #6 on: November 11, 2015, 07:05:30 PM »
Quote from: Blizzard 128 MB;799094
I  do not want to buy a RAM expansion card, or rev. 8 motherboard. I want  to use my rev. 6  1 MB chipRAM motherboard + 0,5 MB fastRAM only.
There may not be big disadvantage, if I expand the motherboard onto 1 MB.[/FONT]

I'm pretty sure that doing the standard rev 6 upgrade to 1mb will just stop the trapdoor ram from working. You can probably hack the motherboard and add extra logic that allows both sets of memory to be used, but I haven't heard of anyone ever doing that. So you'll be the first to figure it out.
 

Offline SACC-guy

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #7 on: November 11, 2015, 07:38:44 PM »
What about the Adram 540 and the Baseboard 4meg trapdoor products.

They both seen to have "solved" the chip and fast ram issue?
 

Offline Oldsmobile_Mike

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #8 on: November 11, 2015, 08:03:17 PM »
Quote from: SACC-guy;799097
What about the Adram 540 and the Baseboard 4meg trapdoor products.

They both seen to have "solved" the chip and fast ram issue?

Sure, he just needs to duplicate the extra logic found on the adapter board:

http://amiga.resource.cx/photos/photo2.pl?id=adram540&pg=1&res=hi&lang=en

ROFL.  :roflmao:
Amiga 500: 2MB Chip|16MB Fast|30MHz 68030+68882|3.9|Indivision ECS|GVP A500HD+|Mechware card reader + 8GB CF|Cocolino|SCSI DVD-RAM
Amiga 2000: 2MB Chip|136MB Fast|50MHz 68060|3.9|Indivision ECS + GVP Spectrum|Mechware card reader + 8GB CF|AD516|X-Surf 100|RapidRoad|Cocolino|SCSI CD-RW
 Amiga videos and other misc. stuff at https://www.youtube.com/CompTechMike/videos
 

Offline Blizzard 128 MBTopic starter

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Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #9 on: November 11, 2015, 08:29:23 PM »
I am shopping only from Europe, I live in Europe.
I  do not want to buy a RAM expansion card, or rev. 8  motherboard. I want  to use my rev. 6  1 MB chipRAM motherboard + 0,5  MB fastRAM only.
A500+ rev. 8 motherboard 1 MB chipRAM + 0,5 or 1 MB fastRAM how possible with trapdoor card?
1 MB chipRAM + 2 or 4 MB fastRAM possible with rev. 6, or rev. 8 motherboards?
0,5 MB chipRAM + 2 or 4 MB fastRAM possible.
JP3 jumper on rev. 6 motherboard function?
« Last Edit: November 11, 2015, 08:42:45 PM by Blizzard 128 MB »
 

Offline mongo

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Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #10 on: November 12, 2015, 02:48:03 AM »
Quote from: psxphill;799096
I'm pretty sure that doing the standard rev 6 upgrade to 1mb will just stop the trapdoor ram from working. You can probably hack the motherboard and add extra logic that allows both sets of memory to be used, but I haven't heard of anyone ever doing that. So you'll be the first to figure it out.


I did basically that, except I piggy backed the extra 512K on the chips on the motherboard because I didn't have a trapdoor expansion.
 

Offline psxphill

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #11 on: November 12, 2015, 10:14:36 AM »
Quote from: mongo;799110
I did basically that, except I piggy backed the extra 512K on the chips on the motherboard because I didn't have a trapdoor expansion.

What exactly did you do?

Quote from: Blizzard 128 MB;799099
JP3 jumper on rev. 6 motherboard function?
[/B][/FONT]

https://ftp.fau.de/aminet/docs/hard/Trouble.txt
« Last Edit: November 12, 2015, 10:18:01 AM by psxphill »
 

Offline paul1981

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #12 on: November 12, 2015, 01:59:21 PM »
Quote from: Oldsmobile_Mike;799095
Why are you making this so hard on yourself?  If you want to add more memory internally why not just buy one of these?  4MB + IDE support for $64 USD.  Or 8MB for the princely sum of $74 USD.  Since it connects directly to the processor this will be real fast ram (like through the side expansion slot), not that fake "slow-fast" ram.  But it's your Miggy, do what you want.


I think he just wants it as authentic as possible for it's time. Like me a bit, I still like my real hdd's. If he wants a modern true fast ram, then the kipper unit is ideal, so the choice is there if he wants it. This would make a 2mb chip plus 8mb fast m/c... Nice A500.
 

Offline psxphill

Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #13 on: November 12, 2015, 02:53:23 PM »
Quote from: paul1981;799119
I think he just wants it as authentic as possible for it's time.


Authentic for an a500 is 0.5mb chip ram.
 

Offline Blizzard 128 MBTopic starter

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Re: Amiga 500 rev. 6A 1 MB chipRAM + 0,5 or 1 MB fastRAM possible?
« Reply #14 on: November 12, 2015, 03:42:29 PM »
Complete, tested Amiga 500+PSU+mouse+disks on ebay.de 45-60 €.
46 €: http://www.ebay.de/itm/Commodore-Amiga-500-volle-Funktion-Top-/171965673114

A508IDE Fastmem with IDE 74 USD:
http://www.kipper2k.com/a500fastmem.html
Shipping to Europe 46 CAD = 35 USD. 74+35=109 USD = 102 €.
A508IDE price = 2×complete A500 config price???!! :shocked: Abnormal.
Shopping impossible.

Complete work A500 config + shipping from ebay.de = min. 70 €.
IDE+8MB expansion 102 €. But CPU = 68000 7 MHz, too slow.
Faster and better CPU 90 €, ACA500, but out of stock.
A508IDE + ACA500 not work simultaneously.
But chipRAM 0,5 MB, too little.
A500+ with 1 MB chipRAM 58 €:
http://www.ebay.de/itm/Amiga-Commodore-A-500-Plus-Altertuemchen-fuer-Sammler-und-Gamer-/121745340679
Ebay.de expansion prices too high.
Simple 0,5 MB trapdoor expansion 20-30 €, 1 MB to A500+ 69 €, etc.
Unreal.
1 MB 29 USD. http://www.kipper2k.com/a500chip.html
A500+ config min. 64 €.
http://www.ebay.de/itm/Commodore-Amiga-500-Plus-/121731739651

The complete A500+ configuration (A500+, KS 2.04, 8373 ECS Denise, 2 MB chipRAM (2 MB Agnus), RTC, 8 MB fastRAM, CFIDE, min. 25 MHz 68000 or 68010 CPU, PSU, mouse, 20-30 disks, 1084S monitor+RGB cable) which can be used well is too expensive, with shipping min. 200-250 €, and no PCMCIA, no AGA.

A1200 100 €, 030/28 MHz 8 MB CPU card 120 €, etc.
http://www.ebay.de/itm/Commodore-AMIGA-MTEC-T1230-28-RTC-Turbokarte-mit-8MB-fur-Amiga-1200-/201455297930
The expanded A500+ price = expanded A1200 price. A1200 = PCMCIA, internal IDE, AGA, etc.
The A500 expansion = meaningless.