Thanks for the video. The only difference between this and a real A500 Plus is that this one will only support 1MB chip RAM. A real A500 Plus with it's Agnus 8375 will support 2MB chip by adding 1 more MB in the trapdoor. With that said, I have built five A500 ++ replica boards. 3 of them are using Agnus 8375. In two of them I opted for the Diet Agnus adapter to allow for Agnus 8372A. Because the 8375s are so overpriced. So two of my A500 ++ replica boards are limited to 1MB chip. Not a big deal as 99.9% of whdload games run fine with 1MB chip. Also, in many of these builds I was transplanting parts from ruined A500 Plus or A500 Rev.6 boards. I did have success in desoldering the 3 legged EMI filters. Alot of heat and old leaded solder. And alot of patience. For a couple of the builds I ordered new EMI filters.
About the ram: I know ;-) Another video ;-) Coming soon ... I tried desoldering (with heat and solderwig) the EMI filters, but they are fragile with age ... and new are not available right now where I live. So project on hold. Which brought me to this video.
@@RetroWK now that you mention it. I had a certain type of EMI filters I desoldered which I discovered had microcracks in them after desoldering. And as I started using my magnifying glass there was a whole bunch of that specific type of EMI filters which had microcracks in them after desoldering. It was the lightbrown with more of a ceramic surface. The more darkbrown ones with a more plastic/shiny surface seemed more solid. Looking forward to more videos from you :)
You need to solder another jumper on the motherboard to use all of the ram. You got 1.5meg but only 1meg shows. And A500 plus uses another agnus also to get 2meg chip support.
4:55 - this is not quite correct. Amiga's CHIP ram was addressable by the CPU + custom CHIP's (hence the name). The Amiga's "other mem" was essentially fast ram or slow ram. However, both where commonly referred to as fast ram. The memory in the trap door shared the bus with the custom chips so if I remember correctly the CPU could only access this memory every odd or even CPU cycle and it was therefore called slow mem. This memory could also be converted to CHIP ram as well by cutting jumpers (which depends on the mainboard version) and as for proper fast ram (e.g. ram not located at the trap door or assigned to the custom chips) the CPU could access this memory anytime it want and therefore it's name fast ram.
I did this with my A500 rev 6a back in the '90s! First put a 2mb Agnus in... then added RAM sockets and RAM... That brought it to 1mb... added a 501 expander to 1.5 mb Later on... I did add the MegaChip (which comes with RAM)... But I think I had to remove the 501 expander. Later on I got a real A500+ and just added a 2mb agnus... Still couldn't use the A501... so it sat with an older A500 collecting dust.. :P
A nice upgrade for a 6a. I have an original mint a500+ (no battery damage, i removed it back in the day) with the full 2mb chip ram. I also have kick 3.1 and a faster cpu 020 with 4mb of fast ram. I also added a gotek and whdload on a cf card. The machine flies and i would say the sweet spot for a 500+. Whdload needs 2mb chip to work properly. Love your channel btw. 👍
I did this way back in 91, except I had to add a wire so it could see the 512k board in the expansion bay as chip ram. I'm interested in the headline at 51 seconds, "or 500 Plus into an A 1200 (almost)" whats that all about? Id love to see that!
Hi, Is it possible to add the ram to the board, and add a memory expansion with gary adapter to have 1mb chip, and the 2mb expansion as slow ram ???? so the expansion will not divide the ram to chip and slow ????
just revisiting some older videos of you. and thats really good to know, that this rev 6a boards are easy to convert, and even better the rev 8a which I bought a short while ago, i dug it up and i was somewhat dissapointed about the state it was in, due the fact that the mouse and joystick ports have some busted pins, and it was very yellowed, but opening it up it was a real happy suprise, dusty but a very good looking board, and to my suprise it even says 500+ on the silk screen, i think what i am seeing is jumper J2 is already set correct, (maybe thats also the reason a game that should work without memory expansion really needed the A502 this time.) now see if I've got a super denise and this extra mem on hand somewhere. So now I know officially, the best way to get a 500+ without the battery cancer is to buy the latest A500 rev 8 and just forget about buying an factory 500+ (zum bestes reconisable by the big badge underneath the embossed amiga logo, then you might have the best chance on having a rev 8 suspectably), dont tell anyone else ;)
@@RetroWK I have the same question - how to enable the trapdoor RAM expansion after you have installed 1MB on the board, if you install the Agnus from the 500+. It’s not the two spots mentioned in this video as those enable the RAM on board but appear to disable the trapdoor RAM. Is there a follow-on video yet? I had a look through your other videos but couldn’t see it. Thanks
When you open the Amiga you find it on the right hand side (maybe it‘s under the floppy and you have to remove that). There is no software to check I know of.
Count the ram chips, if those are 16 than you have a Rev3 (1987 only), Rev4 (rare) or Rev5 (more common). To find out, check the MB right side below the floppy, the Rev5 has a description there. To check for a Rev3, usually a patch wire is present for a fix, by Commodore. If the ram chips are 4, with empty spaces, you have a rev6a (common by 1989) or Rev7 (rare). If it's a Rev8, you'll find 4 ram chips and empty spaces, and the space for a clock battery. Rev8a1 is the A500Plus, same as Rev8 but it counts 8 ram chips and a NiCd battery is present (OMG! Leak Danger!).
I did the jumper mod on my 6A, if you have a 512k expansion card already then after the jumper mod this is seen as chip RAM giving 1MB. What is the advantage of soldering the extra memory directly to the motherboard?
One question, which has been haunting me for years, since I'm no expert on Amigas: Certain games, like Super Hang-on for example, doesn't like the A500+. How do I know that? because I accidentally bought an A500+ thinking it was a regular A500 many many years ago. I put in the disk, and loa and behold, the game would not load or start. I first thought it was a problem with the game, but no , it worked fine on a friends A500. So I sold the A500+ and got myself a regular A500 instead. Why is this an issue? Why create a machine which breaks backwards compatibility with games and software?
This was mainly due to two thing: 1. The Kickstart 2.0 in the A500+ was a compatibility disaster. You can just switch the Kickstart to 1.3 and most programs should run however there is 2. which is that very few games don't play nice with 1 MB of RAM. But if you fix 1. you should be good.
Could you not add another RAM board into the belly to give yourself 2MB of chip RAM? That was necessary with my Amiga 500+. I know that very little software utilizes 2MB chip RAM but what the heck, you might as well go all the way if you can. :)
Not only the 8375, but the super Denise chips are also horribly overpriced. Both need a modern fPGA substitute chip, like the PLA and SIDs for the C64.
Yep. I have some of those around, but that is for a later video. For now this is a stock A500+. The 8375 is not really used unless you have 2Megs of chipram.
Thanks for the video. The only difference between this and a real A500 Plus is that this one will only support 1MB chip RAM. A real A500 Plus with it's Agnus 8375 will support 2MB chip by adding 1 more MB in the trapdoor. With that said, I have built five A500 ++ replica boards. 3 of them are using Agnus 8375. In two of them I opted for the Diet Agnus adapter to allow for Agnus 8372A. Because the 8375s are so overpriced. So two of my A500 ++ replica boards are limited to 1MB chip. Not a big deal as 99.9% of whdload games run fine with 1MB chip. Also, in many of these builds I was transplanting parts from ruined A500 Plus or A500 Rev.6 boards. I did have success in desoldering the 3 legged EMI filters. Alot of heat and old leaded solder. And alot of patience. For a couple of the builds I ordered new EMI filters.
About the ram: I know ;-) Another video ;-) Coming soon ... I tried desoldering (with heat and solderwig) the EMI filters, but they are fragile with age ... and new are not available right now where I live. So project on hold. Which brought me to this video.
@@RetroWK now that you mention it. I had a certain type of EMI filters I desoldered which I discovered had microcracks in them after desoldering. And as I started using my magnifying glass there was a whole bunch of that specific type of EMI filters which had microcracks in them after desoldering. It was the lightbrown with more of a ceramic surface. The more darkbrown ones with a more plastic/shiny surface seemed more solid. Looking forward to more videos from you :)
@@larsenmats Thanks! More videos coming soon!
2MB Chipram or its not an A500+....
You must be fun at parties correcting everyone. @@AmstradExin
Productivity Mode was always nice for word processing.
I had a Atari ST so know little about Amiga so this is really interesting. Thank you.
You need to solder another jumper on the motherboard to use all of the ram. You got 1.5meg but only 1meg shows. And A500 plus uses another agnus also to get 2meg chip support.
Another video ;-) Coming soon ...
Subscribed ! I wonder how i missed your quality channel :)
Thanks! I mostly work undercover ;-)
4:55 - this is not quite correct. Amiga's CHIP ram was addressable by the CPU + custom CHIP's (hence the name). The Amiga's "other mem" was essentially fast ram or slow ram. However, both where commonly referred to as fast ram. The memory in the trap door shared the bus with the custom chips so if I remember correctly the CPU could only access this memory every odd or even CPU cycle and it was therefore called slow mem. This memory could also be converted to CHIP ram as well by cutting jumpers (which depends on the mainboard version) and as for proper fast ram (e.g. ram not located at the trap door or assigned to the custom chips) the CPU could access this memory anytime it want and therefore it's name fast ram.
I did this with my A500 rev 6a back in the '90s!
First put a 2mb Agnus in... then added RAM sockets and RAM...
That brought it to 1mb... added a 501 expander to 1.5 mb
Later on... I did add the MegaChip (which comes with RAM)...
But I think I had to remove the 501 expander.
Later on I got a real A500+ and just added a 2mb agnus...
Still couldn't use the A501... so it sat with an older A500 collecting dust.. :P
I am looking for that MegaChip. Seems to be sold out. I am thinking about using just the PCD from PCBWay and look for the parts.
A nice upgrade for a 6a. I have an original mint a500+ (no battery damage, i removed it back in the day) with the full 2mb chip ram. I also have kick 3.1 and a faster cpu 020 with 4mb of fast ram. I also added a gotek and whdload on a cf card. The machine flies and i would say the sweet spot for a 500+. Whdload needs 2mb chip to work properly. Love your channel btw. 👍
Cool! ... and thanks!
I did this way back in 91, except I had to add a wire so it could see the 512k board in the expansion bay as chip ram. I'm interested in the headline at 51 seconds, "or 500 Plus into an A 1200 (almost)" whats that all about? Id love to see that!
Internet Archive. "Amiga Shopper Magazine Issue 27", page 20
Hi, Is it possible to add the ram to the board, and add a memory expansion with gary adapter to have 1mb chip, and the 2mb expansion as slow ram ???? so the expansion will not divide the ram to chip and slow ????
Yep. That is what I did in the video.
The link in the description to the document does not work 😞
I removed the link. It's not accessible any more ,.. It's just, what I did in the video in writing. You can see the two main pages in the video.
@@RetroWK I found it on the Internet Archive. "Amiga Shopper Magazine Issue 27", page 20
Nicely done!
Thanks!
just revisiting some older videos of you. and thats really good to know, that this rev 6a boards are easy to convert, and even better the rev 8a which I bought a short while ago,
i dug it up and i was somewhat dissapointed about the state it was in, due the fact that the mouse and joystick ports have some busted pins, and it was very yellowed, but opening it up it was a real happy suprise,
dusty but a very good looking board, and to my suprise it even says 500+ on the silk screen, i think what i am seeing is jumper J2 is already set correct, (maybe thats also the reason a game that should work without memory expansion really needed the A502 this time.)
now see if I've got a super denise and this extra mem on hand somewhere.
So now I know officially, the best way to get a 500+ without the battery cancer is to buy the latest A500 rev 8 and just forget about buying an factory 500+ (zum bestes reconisable by the big badge underneath the embossed amiga logo, then you might have the best chance on having a rev 8 suspectably), dont tell anyone else ;)
What does it take to make it see that trapdoor RAM as extra slow RAM? As it seems now, it doesn't recognize it.
There are two spots on the board you need to take care of. It's in the video! Also you need an 8272A Agnus.
@@RetroWK I have the same question - how to enable the trapdoor RAM expansion after you have installed 1MB on the board, if you install the Agnus from the 500+. It’s not the two spots mentioned in this video as those enable the RAM on board but appear to disable the trapdoor RAM. Is there a follow-on video yet? I had a look through your other videos but couldn’t see it. Thanks
how do i see which revision my amiga 500s are? i have two is there some type of diagnostic app?
When you open the Amiga you find it on the right hand side (maybe it‘s under the floppy and you have to remove that). There is no software to check I know of.
Count the ram chips, if those are 16 than you have a Rev3 (1987 only), Rev4 (rare) or Rev5 (more common). To find out, check the MB right side below the floppy, the Rev5 has a description there. To check for a Rev3, usually a patch wire is present for a fix, by Commodore. If the ram chips are 4, with empty spaces, you have a rev6a (common by 1989) or Rev7 (rare). If it's a Rev8, you'll find 4 ram chips and empty spaces, and the space for a clock battery. Rev8a1 is the A500Plus, same as Rev8 but it counts 8 ram chips and a NiCd battery is present (OMG! Leak Danger!).
I did the jumper mod on my 6A, if you have a 512k expansion card already then after the jumper mod this is seen as chip RAM giving 1MB. What is the advantage of soldering the extra memory directly to the motherboard?
I think it does not work with all the memory expansions ... and you have the space for something else.
For me it's always a bit scary when that accent hit's the scalpel :P you never know what's gonna happen :P ;)
Do you really need kickstart 2.x (instead of 1.3) to get 1280x256 screen mode or workbench 2.x software + super denis is enough ?
The internets say you need 2.0 or better. I have not tested that myself.
Where can you find Super Denise these days?
Either ebay or a dead 500+ board … which you can find on ebay 😎
Nice work. :)
Thanks!
One question, which has been haunting me for years, since I'm no expert on Amigas:
Certain games, like Super Hang-on for example, doesn't like the A500+. How do I know that? because I accidentally bought an A500+ thinking it was a regular A500 many many years ago.
I put in the disk, and loa and behold, the game would not load or start. I first thought it was a problem with the game, but no , it worked fine on a friends A500.
So I sold the A500+ and got myself a regular A500 instead.
Why is this an issue? Why create a machine which breaks backwards compatibility with games and software?
This was mainly due to two thing: 1. The Kickstart 2.0 in the A500+ was a compatibility disaster. You can just switch the Kickstart to 1.3 and most programs should run however there is 2. which is that very few games don't play nice with 1 MB of RAM. But if you fix 1. you should be good.
Next project: Turn a A500 into a A1200 ! :D
I think that is a bit more involved ;-)
i see no Amiga sticker on remote
Could you not add another RAM board into the belly to give yourself 2MB of chip RAM? That was necessary with my Amiga 500+. I know that very little software utilizes 2MB chip RAM but what the heck, you might as well go all the way if you can. :)
Yep. There will be a second video about that stuff.
@@RetroWK Excellent! I always enjoy your videos. Thank you!
@@gklinger Thanks man!
Y and Z in the wrong place? On the keyboard
Hehe! German keyboard.
i have amiga 500 rev 6a with 2mb chip ram mod with 8375
Nice. How did you do it? Use the 501 RamExpansion and piggyback the ram chips or something like the MegaChip?
@@RetroWK it is a converter 8372 socet to 8375 with 2mb chip on it
Not only the 8375, but the super Denise chips are also horribly overpriced. Both need a modern fPGA substitute chip, like the PLA and SIDs for the C64.
If people refused to pay that much they wouldn't be overpriced. Obviously some people have too much money.
Didn't the 500+ have 2 meg Agnes
Yep. I have some of those around, but that is for a later video. For now this is a stock A500+. The 8375 is not really used unless you have 2Megs of chipram.
Nice but 1280x256 is so disproportionate, dont believe anyone ever used it.
True! But still nice to know that you could ;-)