I mentioned about C64 Reloaded in my previous post. Let’s talk a bit more about it.
Because here it is!
The C64 Reloaded is a new C64 motherboard. It is recreated according to the schematics of C64B3 model, ASSY NO 250466, and is designed to use the original C64 chipset. A good description you’ll find on the announcement on Individual Computers’ website. Basically, it’s a real Commodore 64, only manufactured with today’s standards.
I haven’t had enough time to spend with this machine to call this a review yet. Instead I’ll share a pictorial overview of the board and some of the nice details on it.
First off, the board looks really nice! It’s the same size as the cost reduced C64E ‘short board’. The chip layout is different, and the board looks much cleaner thanks to the use of modern surface mount components instead of the through-hole parts used in “classic” Commodores. The board itself has a shiny black finish.
Here we have two different C64 models, C64B & C64E, and the C64 Reloaded. The board is exactly same size as the C64E, and all the ports are located where they used to be – with one exception. Note how the RF modulator is replaced with S-Video and audio jacks.
Let’s take a closer look to the new motherboard! Starting from top left corner, here we have one of the CIAs and the C64 ROMs combined into one ROM chip. In the original C64 design, character, Basic and KERNAL ROMs were on three separate chips. The C64E design combined Basic and KERNAL into one ROM chip. Here all binaries reside in one ROM chip, and the 32k chip can hold two sets of ROM binaries. This also means that none of the existing C64 ROM chips are drop-in compatible with C64 Reloaded.
The good news are that two ROM sets can be installed, and switching between them is done by pressing and holding the RESTORE key down for a few seconds (KERNAL), or by holding down RESTORE on reset (character set). Unfortunately C64 Reloaded comes with just the standard ROM set.
Below ROMs, there’s something new – the VSP fix. Some C64s are affected by so called VSP bug, which in essence means that sometimes, some machines can crash when shifting graphics on screen with a certain coding trick. This hardware VSP fix should make the C64 Reloaded unaffected.
Next to these chips sits the CPU in its socket.
On the top left corner just below the screw hole is the circuit that generates the 9V AC for the user port. In original C64, the 9V AC is coming from the PSU, and it’s used to generate supply voltages (+12 V DC) for VIC-II and SID.
Below the VSP fix we got the RAM in two 32k chips like in the C64B3 and C64E designs. Next to the RAM we got some ‘glue logic’ in more modern SMT chips. Compared to the real deal, i.e. original chips around them, the difference in caliber is quite obvious.
Here we have the PLA and VIC-II chips, color RAM sitting between them. Note the jumper setting to select the VIC-II voltage. I really like how the C64R is designed to be compatible with both 65xx and 85xx series chips, found in old and new C64s. The board has to be simply configured accordingly.
I chose my board to be equipped with ZIF sockets, so exchanging the chips is effortless.
Similarly, the board can be configured to be either PAL or NTSC machine, featuring crystals for both clock settings on the board. Setting the jumpers alone is not enough, as there are separate versions of the VIC-II chip for PAL and NTSC. A matching VIC-II chip is needed.
Moving to the right, here we have the SID chip and jumper settings for either 6581 or 8580. The old and new SID chips differ from each other in several ways. Most importantly they run with different voltages (J6). Another jumper (J3) adjusts the output volume. On the left side of the chip you can see two jumpers to set the filter capacitor values (J4+J5).
If I were to swap the included 8580 for a 6581, I would need to remove the filter jumper blocks from J4 and J5, and put them to the voltage (J6) and volume (J3) setting headers instead.
In this shot we can see the remaining stuff around the SID chip. Note the J13 header block in the bottom left corner of the picture. It’s there for stereo SID appliances. The header offers three alternative addresses for a second SID chip, plus audio from the second SID chip can be routed to the audio jack through this header. Very nice addition indeed.
In this picture also the D5 diode can be seen at the upper right corner of the SID chip’s ZIF socket. Much related to the SID voltage-gate seen on certain forums.
Moving on from the SID chip, here we see also a shiny module port cover accompanied with C64 ROMs license. After all, the C64 Reloaded comes with these ROM binaries on an EPROM chip.
Next to the module port is the on-board 5V DC supply, which is rated at respectable 4 amps. Contrary to original C64, the board itself is fed with +12V DC only.
Here’s the power jack on the top right corner of the board. Next to it is the power switch in a familiar place. The switch has a nice little feature – it has three positions: off, on and a non-stay up position, which acts as reset. Great idea!
Keyboard connector is located below the module port, right next to the CIA #1 chip which handles the keyboard and joystick inputs.
In this picture we also see unlabeled, unpopulated header P2. My guess is that this is made available for tinkerers with a VIC-II switcher in mind. This is just my speculation, and time will hopefully tell what this header can be used for.
Here we see a jumper that can be removed to cut power from the cassette port. This reduces idle power usage of the board, as is written on the board. Note the auxiliary IEC port next to the serial connector, port CN4b. In this port we have serial and cassette port lines available. This port could be used for example for internal serial device (uIEC anyone?) or cassette adapter installations.
Here’s another added feature for tinkerers in the middle of the picture. The ‘option select’ can be activated by holding down the fire button on joystick in port 2 during boot. This could control something like, say, selection of second SID chip’s address for example.
Above we see the angled daughter board for S-Video connector and 3,5 mm audio jack.
AV outputs and the serial port from another angle.
This shot should explain why the AV sub board is installed into funny angle. The added S-Video port is available where the RF out used to be for connecting the Commodore to TV with an antenna cable. The audio jack sits in the middle of the hole that used to give access to the RF modulator’s channel selector.
The standard audio and video connectors are really nice addition. The normal video connector is still there, of course.
Talking about video quality, it’s really good, especially when using the S-Video port. When using the S-Video port and a standard cable, the picture is sharp and almost free of any checkerboard patterns on solid colors. If I’m using the ‘normal’ Video port and my S-Video cable, the picture quality is comparable to short board C64s with the new HMOS VIC-II chip with some checkerboard patterns visible.
The picture is at least as sharp as on short board C64s, but unlike with those, the light and dark vertical stripes caused by internal signal interference (check ‘AEC Line Glitch’ on this page) are not as obvious. Of course those signals are present in C64 Reloaded too, but obviously they don’t interfere with video signal nearly as much.
The colors C64 Reloaded output are vibrant and rich. The picture is more saturated than that of C64E model’s.
Back to the unit itself! A look around the corner, and we see that the joystick ports and power/reset switch aligns nicely to the case. The power connector is a lot smaller than it used to be, so there we have some empty space around it.
Not so interestingly, the underside of the board doesn’t offer much thrills.