Cartridges#
The P2000T exposes SLOT1 and SLOT2 for interfacing. The pages as shown below discuss a series of different homebrew cartridge designs.
Simple cartridge
The simple cartridge is the most simple design and a great place to start to learn how cartridge interfacing on the P2000T works. The basic cartridge exposes 16kb of ROM to the P2000T. It is explained how to design such a cartridge, how it interfaces with the P2000T and how a simple program is executed from the cartridge.
Multicartridge
The biggest drawback of the basic cartridge is that it only exposes 16kb of memory of the ROM. Most parallel ROM chips have at least a capacity of 128kb and one would like to make good use of this. The multicartridge offers a simple ROM selection circuit to allow the user to select which 16kb ROM bank they want to expose to the P2000T, allowing one to bundle multiple applications on a single cartridge. Furthermore, some applications can make use of a so-called “soft-reset” feature. The multicartridge uses a 74HC123 multivibrator to give a well-defined soft-reset signal.
ZIF cartridge
The multicartridge has a single parallel ROM chip fixed to the PCB, but this does not offer easy access when one wants to change the content of this chip. Especially in the scenario that one is developing new software for the P2000T and want to test the program on the original hardware, one would like some means of easy access. The ZIF cartridge is very much identical to the multicartridge, but has a ZIF socket on its back side for easy swapping of ROMS.
Cartridge Kit
This project is a cost-reduced version of the multicartridge, meant for hobbyist who would like to build their own cartridge and are comfortable using a soldering iron. The cartridge is designed such that the majority of the components can already be assembled by the PCB manufacturer (e.g. using a so-called assembly service). The user only needs to solder in three more through-hole components and the cartridge is ready to use.
DATA cartridge
The datacartridge is a SLOT2 cartridge to quickly load BASIC programs from. It works via a modified BASICNL cartridge in SLOT1. This latter cartridge has the standard BASIC environment including a few minimalistic routines to load data from the data cartridge into the memory of the P2000T. In a modified boot procedure, a custom launcher application is loaded which interfaces with the SLOT2 cartridge. In this launcher application, the user can select a BASIC program which is inserted into memory while the launcher application is simultaneously removed from the memory upon which the BASIC program is executed.
SD-card cartridge
Perhaps the most elegant solution for loading CAS files into your P2000T is via a cartridge that hosts an SD-card slot. Even the smallest SD-cards have enough capacity to store the complete P2000T tape archive. Reading from such an SD-card is non-trivial and requires both a hardware solution to interface the I/O port of the P2000T as well as a software solution to navigate through the files hosted on a FAT32 partition. This page explains both parts in more detail.