Emuladores de Ajedrez de MESS

Otras participaciones no clasificadas

Moderador: Luis a

Re: Emuladores de Ajedrez de MESS

Notapor CBF » 18 Jun 2018 11:55

Hi Berger,

thanks for your explanation - I think I understand it now.
This 'jumping' between different CPU frequencies also explains the funny name "trampoline" in the driver. :)

I've now implemented these new "CPU Divider" options in my own version, and everything seems to work fine.
I only noticed that the tone signals (beeps) are higher when I decrease the CPU Divider (just as I would increase
the main CPU frequency), so either this is an usual side effect or the reason is, that I'm still using the old code
for the sound hardware ("mono" & "speaker"), because the newer method ("dac" or "vref") is not working in
my old MAME version 0.175.

But at least the clocks are still running correctly when changing this CPU Divider, so it seems the chess program
itself is also still working with the correct CPU frequency (i.e. independent of this divider setting).
I guess this frequency reduction has been implemented at those old times to save battery life, but of course
for the emulator this is not necessary (ok, I know the MAME devs want to make everything as realistic as possible ;))

Regards,
CBF
CBF
Veterano
Veterano
 
Mensajes: 205
Registrado: 21 May 2016 12:13

Re: Emuladores de Ajedrez de MESS

Notapor berger » 18 Jun 2018 12:18

CBF escribió:thanks for your explanation - I think I understand it now.
This 'jumping' between different CPU frequencies also explains the funny name "trampoline" in the driver. :)

I'm glad I was able to clarify the matter a little.

CBF escribió:But at least the clocks are still running correctly when changing this CPU Divider, so it seems the chess program
itself is also still working with the correct CPU frequency (i.e. independent of this divider setting).

Well, not exactly. On these Fidelity computers the time control is obtained from another signal. This was a very good idea on the part of Fidelity's engineers: one way or another (the technique varies) a 600Hz signal is generated as a time base. This signal is independent of the system clock frequency.

CBF escribió:I guess this frequency reduction has been implemented at those old times to save battery life, but of course
for the emulator this is not necessary (ok, I know the MAME devs want to make everything as realistic as possible ;))

This issue was discussed between yovan, hap and me, but now I don't remember the exact conclusions! I think I remember that the main thing is to slow down the access speed to the ROM, because it is usually the slowest component of the system... at least in those times. Also so that an increase in processing speed, in future versions of the same computer, would not affect the access times to the input/output circuits: board reading, LED activation, etc. Let's see if they come up with any more ideas.

Regards,
Berger
Moderador del foro
Avatar de Usuario
berger
Moderador del foro
Moderador del foro
 
Mensajes: 1275
Registrado: 12 Ene 2013 23:00
Ubicación: Barcelona (CATALUNYA)

Re: Emuladores de Ajedrez de MESS

Notapor berger » 18 Jun 2018 13:51

Hola,

Aquí tenéis una foto cenital de una preciosa Fidelity Prestige restaurada, por si queréis incoporarla a CB-Emu. Luis me pidió una foto, pero él no responde a mis e-mails... así que pongo aquí el enlace.

Here you have a zenithal photo of a beautifully restored Fidelity Prestige, in case you want to include it in CB-Emu. Luis asked me for a photo, but he doesn't answer to my e-mails... so I post the link here.

https://photos.app.goo.gl/1EkD7dgdkU39HeJZA

Saludos,
Berger
Moderador del foro
Avatar de Usuario
berger
Moderador del foro
Moderador del foro
 
Mensajes: 1275
Registrado: 12 Ene 2013 23:00
Ubicación: Barcelona (CATALUNYA)

Re: Emuladores de Ajedrez de MESS

Notapor CBF » 18 Jun 2018 18:13

berger escribió:Here you have a zenithal photo of a beautifully restored Fidelity Prestige, in case you want to include it in CB-Emu.


WOW, that's indeed a beautiful picture - many thanks!

Unfortunately due to the wide border the key labels are too small and almost unreadable on a notebook screen.
Nevertheless I've made a layout file for it, if anyone wants this realistic artwork:
https://www5.zippyshare.com/v/uC1xox7X/file.html
Just unzip this into your folder CB-Emu\artwork\fpres (backup or rename your existing fpres.lay before!).
You can do the same for the Budapest version by putting it into the 'fpresbu' folder and renaming the file
to fpresbu.lay.

CBF
CBF
Veterano
Veterano
 
Mensajes: 205
Registrado: 21 May 2016 12:13

Re: Emuladores de Ajedrez de MESS

Notapor Luis a » 18 Jun 2018 19:14

berger escribió:
Aquí tenéis una foto cenital de una preciosa Fidelity Prestige restaurada, por si queréis incoporarla a CB-Emu. Luis me pidió una foto, pero él no responde a mis e-mails... así que pongo aquí el enlace.

Here you have a zenithal photo of a beautifully restored Fidelity Prestige, in case you want to include it in CB-Emu. Luis asked me for a photo, but he doesn't answer to my e-mails... so I post the link here.

https://photos.app.goo.gl/1EkD7dgdkU39HeJZA

Saludos,
Berger


Hola Berger,

Perdona por no haberte respondido. La foto es magnífica, digna de la máquina y estoy trabajando en el artwork, pero me estaba ocupando de otro modelo especial de Fidelity y que fue mi primera máquina en los inicios de los 80. Creo que me costó sobre 30.000 pesetas de la época y se trata de Fidelity Sensory 8.

El artwork existente era éste, muy básico.
Imagen

El que presento:
Imagen

Lo podéis bajar de:
http://www.mediafire.com/file/v6077ukbd ... 8.zip/file

Como siempre hay que descomprimirlo y copiar la carpeta fscc8 en la carpeta de artwork (CB-Emu\artwork).
Y si encontráis algún error me lo comentáis para corregirlo.


Saludos,
Luis
Luis a
Senior
Senior
 
Mensajes: 79
Registrado: 21 Ene 2013 12:35

Re: Emuladores de Ajedrez de MESS

Notapor berger » 19 Jun 2018 16:57

Un trabajo formidable!! :)

Saludos,
Berger
Moderador del foro
Avatar de Usuario
berger
Moderador del foro
Moderador del foro
 
Mensajes: 1275
Registrado: 12 Ene 2013 23:00
Ubicación: Barcelona (CATALUNYA)

Re: Emuladores de Ajedrez de MESS

Notapor yovan » 19 Jun 2018 19:28

hi cbf and others

about the clock divide trick :
in that old time we spoke about Mhz not Ghz as today.
in that time, there were three main components : CPU, RAM, ROM, and of course the peripheral circuitry

the three main components didn't have the same max_speed.
in early 80's, RAM were faster than ROM and CPU.
a little after the CPU was running at speeds compatible with RAM but ROM were still slow.
so the dual speed trick is 'simple' from the concept point of vue.

the clock speed is adapted to the component that is adressed : when it is the RAM it is at 'full speed', when it is ROM it is at 'divided speed', and the CPU of course is able to run at highest of the two speeds.

from the hardware point of vue, the fidelity's implementation is relativly simple : when RAM is adressed (according to the adress bits), the full speed is selected, when ROM is adressed the reduced speed is selected.

exemple for the elegance board :
the max speed is 4 Mhz when accessing RAM and 1 Mhz when accessing ROM

this trick permits to go a little faster than staying always at the lowest speed (1 Mhz).
if we suppose that RAM is accessed in 50% of the clock cycles and ROM at 50% cycles taht makes an average speed of :0.5*4 +0.5+1 =2.5 Mhz
it is better than 1 Mhz even if less than 4 Mhz.
the 50%/50% is not the real percent, it is just for understanding the process, and there are also some access to the peripheral circuits to interface with leds, sensory membrane, ...

using modern chips you can make some miracles in those configs, running all the board at full new _spped, new_speed being bigger than 4 Mhz.

regards.
yovan
novato
novato
 
Mensajes: 10
Registrado: 22 Mar 2017 21:00

Re: Emuladores de Ajedrez de MESS

Notapor CBF » 19 Jun 2018 21:15

Thanks yovan for this very informative description! :)

So this means that the affected Fidelity modules were running too fast in MAME/CB-Emu
before this CPU divider was implemented (of if this divider is disabled), right?
Do you have any experience values, how much % this speed difference could be?

CBF
CBF
Veterano
Veterano
 
Mensajes: 205
Registrado: 21 May 2016 12:13

Re: Emuladores de Ajedrez de MESS

Notapor Luis a » 21 Jun 2018 21:26

Esta es mi artwork de Fidelity Prestige:

Imagen

Como suele suceder con muchos modelos los textos de los botones son muy difíciles de leer, por lo que los he reescrito capturando el color original y aumentando las fuentes.

http://www.mediafire.com/file/p81pvpfgz ... s.zip/file

Descomprimir en la carpeta CB-Emu\artwork. Para la versión Prestige Budapest tenéis que copiar la carpeta fpres como fpresbu y renombrar el lay como fpresbu.lay

Saludos,
Luis
Luis a
Senior
Senior
 
Mensajes: 79
Registrado: 21 Ene 2013 12:35

Re: Emuladores de Ajedrez de MESS

Notapor berger » 22 Jun 2018 07:23

Hola,

Un trabajo excelente, Luis. Ha quedado precioso.

Por cierto, cuando tengas un rato te agradecdería que echaras un vistazo a este enlace:

viewtopic.php?f=19&t=842

Tienes un montón de trabajo hecho pero muy disperso. Me pregunto si podrías agruparlo todo en un archivo para reducir el número de enlaces de descarga.

Saludos,
Berger
Moderador del foro
Avatar de Usuario
berger
Moderador del foro
Moderador del foro
 
Mensajes: 1275
Registrado: 12 Ene 2013 23:00
Ubicación: Barcelona (CATALUNYA)

AnteriorSiguiente

Volver a GENERAL

¿Quién está conectado?

Usuarios navegando por este Foro: No hay usuarios registrados visitando el Foro y 1 invitado

x