Itt a DRVTEST, egy kis alkalmazás hajlékonylemez-meghajtók és EXDOS kártyák teszteléséhez, diagnosztizálásához és vizsgálatához.

Azért írtam, hogy segítsen az EXDOS 3 fejlesztésében, valamint segítsen a öreg hardverek életbentartásában.

A DRVTEST.COM betölthető a BASIC-ből, vagy futtatható IS-DOS parancsként, vagy a DRVTEST.ROM behelyezhető egy ROM-ba, és a következővel indítható :DRVT.

Egyes helyeken meglehetősen technikai, de a H gombbal elérhető HELP leírás. Vagy csak válasszon meghajtót A vagy B gombbal, majd nyomja meg a T gombot a Tesztek futatásához meghajtó vizsgálatára!

A little taste / tease...



No promises, still quite a bit of work and testing to do... : Lol:

The new Spectrum-like games console seems to be in trouble according to  BBC news story but scroll down a bit...look who one of the backers is...Dr Levy!

(Sorry if everyone already knew that, I didn't!)

A few people have asked about EPNET progress recently so I thought I'd start a new topic for everything to do with EPNET.

Recent work
After the problems I had with glitches on the Enterprise's /RD and other z80 signals on the expansion bus (described in painful detail in other topics ), and after discovering that a few original EXDOS cards include a fix , I have copied the fix and applied it to EPNET. This involved a new revision of the PCB which I am calling EPNET 1.2. (1.0 was my first version, and 1.1 was an intermediate version that never got made).

EPNET 1.2
EPNET 1.2 also includes: A compact FLASH card interface, nearly 512k expansion RAM, the ability to enable 64k FLASH ROM for any other ROM images, the ability to sit between the Enterprise and other expansion such as EXDOS, and the ability to live in a box.



Current state
I hope to be able to send out two "beta" prototype cards soon time for further testing in environments other than my little workshop. For example I have not tried it with 8 or 10MHz machines or with any Enterprises other than the 3 I own. I am particularly nervous about the last point given my /RD noise problems

If that goes ok I have enough parts and PCBs to build 7 more. While I am doing that I will need to order more parts and PCBs which will have a lead time of several weeks.

I hope to make it available as a vertical naked PCB as shown above (which can also be plugged into an expansion bus), a vertical box, or a horizontal box as shown above. (No photo yet of the vertical box as I am still working on it! ). The box versions sadly will have to be more expensive due mostly to the cost of the box itself.

Future
ESP8266 version: it should be possible to make a wireless version by just replacing the network module. But so far I only have a half-built prototype.
EXDOS integration: I would like to be able to map a drive letter to a network directory so that EPDOS etc works with a network directory. This requires a lot of work with EXDOS but that should also lay the ground work for FAT16 or possibly even FAT32.

This project is only a "hobby" in my spare time so no guarantees of timescales. I am going as quickly as I can but there are lots of other demands on my time particularly in the summer months! .

For £7.99 one of these from Amazon https://www.amazon.co.uk/gp/product/B010A6WB0A/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 needs 5V @ 15mA and GND, and outputs ASCII lines at 4,800 baud. It is a satnav-type module and uses the satnav satellites to output your position, but one of the lines it outputs is the current time (UTC)! (Other similar modules are available, it is a standardised protocol and they are intended to connect to a car dash camera to allow the camera to record your position.)

Unfortunately 5V is not on the EP serial connector but maybe if RTS was always high it could be used to power the unit!

Here's a trace taken on an EXDOS card plugged into the expansion port of a standard EP128:




The purple trace is /RD and the blue trace is the same signal after it has passed through an OR gate (other input tied low) on the EXDOS card. The dotted horizontal line is at 0.8v - the "0" to "1" threshold for LS TTL.


Here's the same signal, /RD, on my EPNET card (different timebase on 'scope though):




Just wondered if anyone else has seen this before?

B.

Here's a trick I didn't know about/had never thought of. I can't claim credit for it: I've just come across it at http://map.grauw.nl/articles/fast_loops.php.

Basically it's unrolling LDIR into a series of LDIs. Easy if you know in advance how many bytes but here's some general copy code that's nearly 20% faster (with a little overhead). It's self-modifying so won't work in ROM!

;
; Up to 19% faster alternative for large LDIRs (break-even at 21 loops)
; hl = source (“home location”)
; de = destination
; bc = byte count
;
FastLDIR:
    xor a
    sub c
    and 16 - 1
    add a,a
    di
    ld (FastLDIR_jumpOffset),a
    ei
    jr nz,$  ; self modifying code
FastLDIR_jumpOffset: equ $ - 1
FastLDIR_Loop:
    ldi  ; 16x LDI
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    ldi
    jp pe,FastLDIR_Loop
    ret

I'm not sure why the di and ei are needed unless you're going to use the same code in an interrupt routine and main code.

Here is a tiny new module that can connect a device to WiFi over serial  : (it does SPI too)

http://www.seeedstudio.com/depot/WiFi-Serial-Transceiver-Module-w-ESP8266-p-1994.html

It is aimed at the "internet of things" but I don't see why the Enterprise could not be a "thing"  It has a nice soldering iron friendly 0.1" connector!

It would be slow of course - the max baud rate of the Enterprise is 9600 . But it would be easy to connect up without interfering with disk drives/SD card readers etc on the main expansion bus or cartridge slot. It contains the TCP/IP stack so would just need the SMB or FTP protocol to run on the Z80. (Q: is it possible for a 4Mhz Z80 to go faster than 9600 without extra h/w assist? [without disabling interrupts for ages])