The final Amiga hardware project of the year for me is this nice mini hardware kit for the Amiga 1200, the OpenA1200RTC. A real time clock that you can hook up to an Amiga that has a clock port. Find out more about the OpenA1200RTC here. The real time clock makes the Amiga 1200 keep track of time.
Building the OpenA1200RTC
This was a very simple 20 minute build containing only 13 parts. The only moderately difficult to find part is probably the RTC chip which can be found on Ebay or AliExpress.
What is the clock port in an Amiga?
The Amiga 1200 has a port fameously dubbed the ”clock port”. The clock port is a 2 mm double row 22 pin header close to the CPU slot. It was rarely used for its intended purpose, to host a real time clock, since hardware engineers figured out how to hook up sound cards, serial ports and other things to it.
There are some Zorro cards that also has clock ports. That means it is possible to run clock port hardware on a big box Amiga that can carry Zorro cards.
So what do you use an RTC for anyways on an Amiga?
The main purpose of having an RTC such as the OpenA1200RTC is for the Amiga to not lose time when it is powered off. Having your computer keep track on time is not only usable for having a clock on the desktop. If the computer keeps track of time, that means all files will have timestamps whjen they where created or last edited. While it is possible to sync date and time with a server over the internet it could be handy to have an internal RTC on an Amiga that is not hooked up to the internet a majority of time. Also, it could be nice to finally use the clock port for its intended application once.
BFG9060 with rev 1 68060 under testing in my A4000TX
I built a BFG9060 060 turbo card last year that I could clock at 100Mhz, this is the second BFG9060 I have built and it is in a cool red PCB color. Thanks to the Xilinx programmer I got I could finally program the CPLDs on it but did not have time testing it fully. Now that I have tested it I can finally confirm that it is working 100%.
Actually, I just ran Quake for an hour with it mounted in my primary Amiga, my A4000TX daily driver, and the card performed just fine. Once I have it permanently installed in one of my big box Amigas I will do a proper 24h POVRay fish render test. But as it is now, I am happy with how it performed!
Mystery 68060 CPU
I got this 68060 chip from Vesalia years ago (probably 12+ years ago), and for a really good price too. It was a deal too good to pass on even though I did not know what to do with it. Well I am happy that I kept it but for all these years I wondered three things:
Did it work?
What kind of 060 was it?
Is it a fake? Why did it have these strange markings and not the typical Motorola markings?
The answer to those questions are:
Yes the 68060 works fine! And it does not get that hot either (though I have a heatsink/fan on it).
It is a rev 1 68060.
It is not a fake 060 – It came from a Phase 5 turbo card – Phase 5 used to add this text to the 060s on the turbo cards.
While the CPU works, it is a little bit of a bummer that it is a rev 1 as that revision has bugs. But there are work arounds for that so it does not really matter. Unfortunately, as its rev 1, that means no 100Mhz overclock. But to be honest with you, I am glad just having another full (MMU/FPU) 060 on a big box Amiga turbo card.
68060 low profile 5v cooler
I was afraid that the CPU I had was going to run too hot so I went into my stash of heatsinks to look for a suitable cooler for it. I found this thin 5v laptop cooler that I must have kept in my stash for more than 15 years. I got it from an old Acer Celeron laptop I found in the trash at a job I had and I was glad I finally found a use for it.
It is a thin radial fan that sits on an aluminium bottom plate that acts as a heatsink. I have not found modern alternatives in this size for a good price so I guess they have become rare these days.
I used thermal adhesive tape (also called ”frag tape” BITD) to secure the heatsink to the CPU. Believe me, this thermal double sided adhesive tape has insane stickiness, there is no chance of the heatsink falling of the CPU if mounted vertically.
I can confirm, according to tests done with my finger, that the CPU does not run hot at all with the heatsink/fan on it. I am starting to wonder that maybe it was overkill, but if I end up using it in an A3000D case it might come in handy as that case has poor cooling performance.
I built a ReAmiga 1200 late last year using a black PCB. Once finished with that I knew I wanted a backup A1200. I usually buy systems in pairs, one for usage and one for backup or testing purposes and I always have a purpose for stuff I get since I do not believe in hoarding up stuff for hoarding purposes only. The first ReAmiga 1200 I built had a black PCB and is mounted in a black A1200.net case so I decided to go for another color. The only color I found, since I did not want to order PCBs myself, was white so thats what I got.
Closeup of the white ReAmiga 1200 motherboard
As with the last ReAmiga 1200 PCB I built this build went really smooth. I used components from a broken A1200 PCB that I desoldered with an hot air rework station. I also got connectors from that donor board. Other stuff like the PCMCIA connector and the odd chip here and there was ordered from AliExpress, Sordan and from ebay.de. Off course the majority of passives and some chips came from Mouser. This time I used the same color for all LEDs for all LEDs -green- unlike my last one that looks like a christmas tree when powered on. I sort of wish I ran all red LEDs, perhaps if I build a third one.
The motherboard is inserted into the original Commodore A1200 case
I was thinking of keeping this PCB in storage or getting a white A1200.net case but then I remembered that I had a genuine Amiga 1200 case in storage. Most A1200 cases are in bad shape these days but this one was actually in relatively fine shape. Notice the Centurion tech backplate that I used instead of the metal shield. It looks professional but I think it fit the replica cases better.
Even the floppy drive and cables was original (not the screws though)
As a bonus, that case had all the parts to make it a full A1200. The floppy drive, cables, LED lights for HDD, floppy and power and the keyboard.
Here is the ReAmiga 1200 fully built in the Commdore A1200 case with orginal keys.
And believe it or not, the threads of the case was not stripped or cracked, the keyboard was relatively white too and had not gone too yellow over the years. Testing the system (there is no HDD inside it) it works fine and I actually did have a plan for this system, sometimes in the future when the scandoubler arrives for the PiStorm32 I will try PiStorm32 on it. But as it stands right now its going in storage.
Programming the Prometheus on my A4000T motherboard, in order to program the chips they have to be powered up, thats why the Amiga is powered up
A lot of Amiga hardware projects uses programmable Xilinx chips, also called CPLDs, (Complex Programmable Logic Device). These chips are supposed to be programmed with logic. Previously I have used a RaspberryPI as a programmer following the excellent guide Linux Jedi set up for programming a CPLD with an RPI. This has worked well, but I got stuck on a few projects where the RPI could not handle the CPLDs.
Disadvantages and advantages of programming Xilinx CPLD with Raspberry Pi
The advantage of programming a Xilinx CPLD with a Raspberry Pi is that its a cheap programming solution that is fine for the occasional project that needs a CPLD programmed.
The disadvantage is that a Raspberry PI can not program a CPLD that has been write protected. Many Xilinx CPLDs on eBay and AliExpress has been previously used or are unused but already preprogrammed chips. It has happened to me that the chips I got from Chinese sources has been write protected which is a problem since you can not write to a write protected CPLD with an RPI. Another disadvantage of programming CPLDs with a RPI is that there might be cases where the RPI can not handle the programming. I have seen that happen on projects that uses CPLDs in a chain from different makers for example.
Using a Xilinx programmer instead
I got this DLC10 Xilinx programmer from AliExpress, as with most stuff there, this is probably just a fake or clone of the genuine thing. But it works fine. As with most programmers there is a little learning curve in how to set up the software for the programmer. In this case the programmer was in a virtual Linux installation that had to be run with VirtualBox. I highly suggest googling for a tutorial on YouTube for learning how to program CPLDs with a Xilinx programmer to minimize confusion. Once done a couple of times it becomes second nature.
Amiga projects with CPLDs that I programmed with my new Xilinx programmer
Firebird A4000D is now fully programmed, should add all PCI slots to it and try out some PCI cards on my A4000D!
I had a couple of projects in my stash that was stalled because they refused to be programmed with a RPI. These where the Prometheus PCI board (had a CPLD that was write protected).
BFG9060 fully programmed and confirmed working in my Amiga 4000D
The second BFG9060 I built (also had a CPLD that was write protected) and the Firebird A4000D that used Altera and Xilinx chips on the same chain. All projects where programmed fine and it was very satisfying the be able to move on and closing projects thats been in a state of limbo for close to a year!
This is the second GBAPII++ Amiga graphics card I have built. I finished the last bit of the build two weeks ago. Today I tested it in my Denise Amiga clone and could confirm that it was working fine. If you are interesting in building one yourself, check out more information about the graphics card here. There are some details about the background of the card there too.
Hardware specs
The GBAPII++ is a Zorro 2 based Amiga graphics card based around the Cirrus Logic GD5434 chip. It has 2 MB memory and is a relatively affordable Amiga graphics card. Occasionally you see users referring to the card as an open Picasso 2 card as you can order empty PCBs yourself and build it. But if you know Amiga hardware well this card is based on another chip. The similarities are close though, both cards has only 2 MB and is probably likewise in performance as they are both Zorro 2.
The VGA adapter plate has both output and input so its possible to run scandoubler output through one VGA output, very handy and a must have these days IMHO. I use mine with a Indivision MK3 and it works perfectly out of box. Or run it with the Multivision-AGA scandoubler.
It is possible to use the card on an Amiga 500 by soldering an 86 pin 2.54mm edge card slot to the side of the card, thats probably why the graphics card goes by the name A500-GraKa.
Components
The graphics card is based on the Cirrus Logic GD5434 chip
If you are thinking about building one I suggest you go looking for a GD5434 chip first. These chips are not impossible to find but can be pricey. I have paid between 20 to 40 euro each for Cirrus Logic GD5434 chips (currently have built four cards based on this chip). Finding an old VGA card and desoldering a chip with hot air is also a possibility.
The memory used is the same type of memory that is used in an Amiga 1200 1.4d revision. The typical SOJ40 2MB memory chips in the quantity of 4 chips.
I had difficulty finding the correct voltage crystal but eventually found the right one on AliExpress (and it worked too).
Building the graphics card
For some reason I thought building this card was incredibly confusing. I think the main reason is that I somehow got the build instructions for a previous revision of the A500GraKa card, once I got the correct file everything worked out fine! IIRC there are some solder pads marked as ferrite beads that should take resistors (or it was the other way). To find out what components go where one can look into the designer files, also study the BOM.
Performance
The graphics card works especially fine in lower resolutions and fewer colors like this 800×600 8 color Workbench
I have not tested performance yet and will probably never do, but make no mistake, this is no competition for a ZZ9000 graphics card. It is a fine card to use on a 030 based Amiga with a Zorro 2 bus as long as one do not go crazy on the amount of colors or resolution used. It is much better than using hires laced. I stick to 800×600 in 8 colors and it works fine.
Conclusion
The graphics card is hooked up to the VGA adapter plate that is fitted to a3D printed bracket
Many thanks for the creators of this card and previous cards it is based on. I think this card is a no brainer, just get one if you have an empty Zorro slot and no graphics card. I will list the good things first and negative later, these are strictly my personal opinions.
Positive
Half size card
Has a hole cut out for your finger so you can remove it easely
Autoswitch between scandoubler/VGA
Open card, PCBs can be ordered by yourself. There is also commercial version of it
There is a thread on a1k.org where you can ask questions about the card
Supported in P96 (so you can install the card with the P96 installer)
Negative
Somewhat confusing build instructions
Only has 2 MB
Is a Zorro 2 card so its slow (but still perfectly fine for lower resolutions/fewer colors)
Here is Doom running on the GBAPII++ Amiga Graphics Card
