ZX Spectrum DivIDE Plus Hard Disk Interface

(Firmware)

ZX Spectrum

Overview

Storage Solutions

The DivIDE Plus Hard Disk Interface is supplied with 4 different firmwares loaded into its on-board ROM chip. You can switch between the firmware at any time using the OUT 23,x command but how do you decide which firmware to use. This is currently set to allow the following BASIC command:

OUT 23,x : USR 0

where x is:

0 - FATware
2 - DEMFIR
4 - +divIDE
6 - MDOS
73 - ResiDOS

Firmware is the program which allows the ZX Spectrum to talk to the hard disk or compact flash memory card, allowing you to read and write software as required.

We are working on a short program which allows you to select the firmware when you start up the DivIDE Plus interface.

DivIDE Plus supports the following firmware which was produced for the original DivIDE interface:

FATware 0.12 natively supports up to 8 standard FAT-16 partitions (including long file names). It loads TAP, SNA, Z80, SCR and interlaced SCR files. With FATware you don't need any low-level disk utilities to get up and running - just unplug your disk or CompactFlash from your PC and plug it into your divIDE. NOTE: This is read only.

DEMFIR (DTP's Emulator Files Runner) handles ISO 9660 file system found on CD-ROMs. You can use either CDs or unfragmented ISO images stored on a disk. DEMFIR supports TAP, SNA, Z80, MFC and SCR files. You can download these from numerous software archives such as World of Spectrum. As it is possible to fit thousands of games onto a single CD, DEMFIR can turn your Speccy into huge retro-gaming console. NOTE: DEMFIR is read only.

MDOS3 is a divIDE enhancement of MDOS/MDOS2 systems which were used in D40/D80 disk units. MDOS3 is a full-featured OS working with raw diskette images and supporting up to 4 virtual drives. One of its divIDE-specific add-ons is a tape emulator. With huge D40/D80 software base available this is worth a try, especially if you're a former Didaktik user.

+DivIDE is an adaptation of the GDOS/G+DOS system found in the DISCiPLE/PlusD disk interfaces. It should work with all DISCiPLE and +D software which doesn't call routines in GDOS/G+DOS ROM directly. +DivIDE uses virtual disks of 1600 sectors each on the ATA drive. Certain GDOS/G+DOS features are extended and improved. NOTE: +DivIDE uses raw LBA access to disk images so take care if you're hosting another file system on your disk. The author is currently looking at +DivIDE to provide additional facilities as described below.

TBIOS is basically a hardware testing utility and not supplied. TBIOS source code is available for starting developers as a demonstration of how to interface with ATA devices, how to handle shadow ROM entry points etc. Some goodies are included, such as divIDEo player and dithvIDE picture viewer. We do not include TBIOS with DivIDE Plus at present.

However, DivIDE Plus offers the advantage of extra memory over the original DivIDE interface, which allows it to run enhanced firmware. As a result, users can also use:

ResiDOS - this adds a whole host of facilities to the Spectrum and can utilise the additional RAM supplied by the DivIDE Plus interface as a fast battery backed ramdisk. It includes facilities to read from and write to compact flash memory cards and hard disks in either IDEDOS format (which can be used directly with the Spectrum +3e ROM) or created on a PC or MAC (in FAT-16). It therefore is the first firmware which makes it easy for Spectrum users to transfer files both ways between the ZX Spectrum and the PC.

ResiDOS also includes the ability to load various packages from compact flash, which even includes a ZX80 and ZX81 emulator to run on your Spectrum. It is hoped that ResiDOS will soon be able to run a port of the CP/M operating system.

Please note that because ResiDOS is stored in battery backed RAM on the DivIDE Plus, it can sometimes become corrupted - you can download Residos and reinstall it by copying the supplied file onto your compact flash card, selecting it under FATWare and then using LOAD "".

+DivIDE - the author is currently looking at enhancing this firmware to provide extra functionality for the DivIDE Plus hard disk interface, including the possibility of using a Plus-D floppy disk interface at the same time as your hard disk.

More firmware is planned for the DivIDE Plus, including:

enhanced version of +DivIDE
CP/M 2.2 QED by Jarek Adamski
ZXVGS by Jarek Adamski
ESXDOS by LaesQ
Possibly an enhanced version of MDOS3