Next: CBM-II emulator features, Previous: VIC20 emulator features, Up: About VICE [Contents][Index]

### 2.5 PET emulator features

The PET emulator emulates the 2001, 3032, 4032, 8032, 8096, 8296 and SuperPET (MicroMainFrame 9000) models, covering the whole series. The hardware is pretty much the same in each and that is why one single program is enough to emulate all of them. For more detailed information about PET hardware please refer to the PETDoc file.

Both the 40 column and 80 column CRTC video chips are emulated (from the 4032 onward), but a few of the features are not implemented yet (numbers of rasterlines per char and lines per screen). Fortunately, they are not very important for average applications.

The PET 8096 is basically a PET 8032 with a 64KiB extension board which allows remapping the upper 32KiB with RAM. You have to write to a special register at `$fff0` to remap the memory. The PET 8296 is a 8096 but with a completely redesigned motherboard with 128KiB RAM in total. Of the additional 32KiB RAM you can use only some in blocks of 4KiB, but you have to set jumpers on the motherboard for it. VICE uses the command line options ‘`-petram9`’ and ‘`-petramA`’ instead. Also, the video controller can handle a larger address range. The PET 8x96 model emulations run the Commodore LOS-96 operating system - basically an improved BASIC 4 version with up to 32KiB for BASIC text and 32KiB for variables. See PETDoc for more information.

The PET 8296D is an 8296 with built-in 8250 low-profile dual disk drive.

The PET 8296GD is an 8296D with additionally a "HiRes Emulator" (HRE). This is a cheaper version of a "HRG" hi-res board which was based on Thomson chips. This version instead uses no additional hardware support apart from some memory mapping tricks. It has supporting software in the hre-*.bin rom files.

The SuperPET also is a PET 8032 with an expansion board. It can map 4KiB at a time out of 64KiB into the `$9***` area. Also it has an ACIA 6551 for RS232 communication. The 6809 CPU that is built into the SuperPET is now emulated, since release 2.4, including the 6702 dongle chip.

The Super-OS-9 MMU expansion, developed by TPUG (Toronto PET Users Group) is also emulated.

The PET computers came with three major ROM revisions, so-called BASIC 1, 2 and 4, all of which are provided. The PET 2001 uses the version 1, the PET 3032 uses version 2, and the others use version 4. The 2001 ROM is horribly broken with respect to IEEE488 (they shipped it before they tested it with the floppy drive, so only tape worked. Therefore the emulator patches the ROM to fix the IEEE488 routines.

As well as other low-level fixes the 2001 patch obtains the load address for a program file from the first two bytes of the file. This allows the loading of both PET2001-saved files (that have $0400 as their load address) and other PET files (that have $0401). The PET2001 saves from $0400 and not from $0401 as other PETs do.

Moreover, the secondary addresses used are now `0` and `1` for load and save, respectively, and not arbitrary unused secondary addresses.

To select which model to run, specify it on the command line with the `-model MODEL` option, where `MODEL` can be one of a list of PET model numbers, all described in see Changing PET model settings

Next: CBM-II emulator features, Previous: VIC20 emulator features, Up: About VICE [Contents][Index]