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The ACF 5 - work in progress

The ACF 5 is a 96kB RAMpack and a Compact Flash mass storage device. We have also included a reset button. This is only part 1 of the project to get a mass storage solution for the Ace. The extension to the Aces ROM to save and load tape files to the CF card are next to be worked on. A new ROM board has been designed by Edwin to house the EPROM more on that in the next few months we hope.

For more on the ACF devolvement see ACF 4, ACF 3, ACF 2, ACF 1.

December 2006

The test pcbs have come back as you can see below:

component side    Solder side

With the components added it looks like this:

With the P11 CF adapters in place it looks like this:

Powered up with an Ace.

The P11 CF adapters.

These are CF Card adapters we purchased from China [ see here ] they come as a pack of three. To use them with the ACF5 you will need to make a small modification to them. So that they will work together as a Master and Slave drives.

If you take a closer look at the images below you can see that we have removed two LEDs. But most importantly is that Edwin fixed the DASP signal by adding a small wire feed from the GREEN LED top solder point to pin 39 which was not connected at the connector. There is a track on the ACF5 pcb that connects these two signal together. This patch on the P11 boards makes the DASP signal available at the connector. DASP stands for Drive Active/Slave Present.

Note: The black wire patch for the DASP signal. On the left P11 adapter its taken from the removed green LED top solder point to pin 39. On the right P11 adapter its taken from the back of the card and its just visible on the right where its soldered to pin 39.

A back view of the P11 adapters, the left one nothings added as the patch is on the front see above. But the right P11 card you can see the wire patch soldered to the top solder point of the green LED then the wire goes across the board to be solder to pin 39 on the front of the card see above image. All that's needed to do now is to set the jumpers on the cards so one is a master and the other a slave. Also set the jumper to power the adapters from pin 20 [5v+ signal] on the IDE socket.

The RED LED is to show that there is power to the P11 boards. The GREEN LED is the activity led and flashes when data is being read or written to the CF cards, Master or Slave. The YELLOW LED is on when a CF card is detected, otherwise it is off.

RAM pack memory bank Paging on the ACF5

On power up you can use the RAM as any normal 48K extension with the Aces Forth.

Paging Memory bank AceForth words. First clear the RAMTOP to below 16384: 16383 15384 !
Then type in the following three words of Forth.


CODE PAGE0 175 C, 237 C, 79 C, 253 C, 233 C,

CODE PAGE1 62 C, 128 C, 237 C, 79 C, 253 C, 233 C,

Now you will have two new AceForth words PAGE0 and PAGE1. Which will swap the two 48K pages, the LED will be bright to show which page is currently in use.

Just a note that when you swap pages you also swap the return stack that's why we lowered the RAMTOP to below 16384. You could make a Forth word to move the return stack to the PAD swap pages then copy the return stack to the new memory page. One other thing! if you have an AceForth word definition which crosses over the 16384 page boundary you will have a crash then swapping pages. A possible solution is the reserve a few bytes of RAM which crosses the page boundaries. We will be looking at these words soon.
Schematic and board images from Eagle.

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