Cluso's MiniBlade2 - possible mini P2 1.0"x1.6" - any interest ???

Cluso99

Here is a possible new P2 mini I've been working on...

Cluso's P2 MiniBlade2

* PCB 1.0"x1.6" 2 layer ENIG 1.0mm FR4 (note 1.0mm)
* P2X8C4M64P Rev C chip of course
* 20MHz xtal
* Requires 5V regulated input (from 0.1" USB/TTL header)
* 3V3 1A LDO SOT-223
* 1V8 1A LDO SOT-223 (fed from 3V3 regulator)
* Bulk and bypass capacitors (not as quiet as RetroBlade2 board)
* Transistor reset circuit (as per P1) (maybe without configured with solderable link)
* microSD socket (microSD card not supplied) - can boot direct from microSD without Flash
* P00-07 brought out on 1x10pin 0.1" header (with 3V3 and GND)
* P32-39 brought out on 1x10pin 0.1" header (with 3V3 and GND)
* P58-61 used internally for microSD and (optional) SPI Flash
* P62-63 brought out on 1x6 0.1" header (serial port) for Reset/SerialOut/SerialIn/5Vin/Gnd/nc - compatible with CP2102 USB-A/TTL 6pin (not supplied - fleabay ~$1.50)
- considering swapping 5V & GND to use the new CP2102 module with microUSB connector (uses different pinout ) - fleabay ~$1.50
* Optional SOIC-8 (possible XSON8) footprint on underside for Flash W25Q32JVSIQ/W25Q64JVSIQ/W25Q128JVSIQ (4/8/16MB Flash)
* Through hole parts supplied but not fitted/soldered
* Price without flash USD $45 posted unregistered airmail from Australia
* Price with flash USD $50 unregistered airmail from Australia
* If there is enough group orders to the USA, I'm sure Publison will repost locally.

Notes:
* The regulators will likely self-limit to somewhere in excess of 500mA. Switchers are not used.
* The 3d image does not show the microSD connector (see photos of my RetroBlade2)
* A 1x2pin 0.050" header/link (solderable??) enables the 10K pullup resistor (fitted as standard) for booting from the (optional) Flash chip

This pcb is very tight and I haven't completed it yet. It's a tiny pcb with limited I/O. This required some limitation in how I can route the bulk and bypass capacitors and may therefore slightly compromise the ADC performance. Switchers are not used for the regulation and will therefore possibly limit overclocking and pushing the P2 to its' limits. IMHO this is an acceptable design limitation. I have a couple of ideas too.

One question...
The CP2102 now comes in two options on fleabay. The older one has a full size USB plug onboard, while the newer one has a microUSB socket. Unfortunately, they swapped the 5V and GND pins around. The newer board is smaller and nicer but my RetroBlade2 uses the older CP2102. The newer CP2102 also does not have the 0.1" pins soldered so that a socket could be fitted to this pcb, and male pins to the MiniBlade2. This would help prevent plugin errors if you have both. Do I swap to the newer pinout???

CP2102 older pinout 3V3, DTR, RXD, TXD, GND, +5V
CP2102 newer pinout      DTR, RXD TXD, +5V, GND, 3V3

https://ebay.com/itm/CP2102-USB-2-0-to-TTL-UART-Module-6Pin-Serial-Converter-STC-Replace-FT232-Part/183568878277?hash=item2abd8ecac5:g:M40AAOSwuQhcB3PW
https://ebay.com/itm/MICRO-USB-to-UART-TTL-Module-6Pin-Serial-Converter-CP2102-STC-Replace-FT232-D/112049647905?hash=item1a16adf121:g:a~gAAOSwWdNcNq1W

Is there any interest if I proceed with making boards ???

hinv

What would be the advantage of this one besides being easier to produce and smaller? I really like my RetroBlade2.
If you do make it, may I suggest a quality push-push style microSD socket?

hinv

Also, since not that many pins are brought out, would it make sense to bring more to the microSD so that QPI or better could be used?

Tharkun

I am interested in one, the newer CP2102 pinout would be nice

K2

hinv wrote: »

I really like my RetroBlade2.

That's kind of my deal too. You're a victim of your own hard work and success, Cluso.

Dave Hein

Cluso99, I like the basic idea, but as you know I would be more interested in something like the P2 Edge, but in a DIP format. That is, with just a flash chip and no SD card, and maybe more I/O pins. So basically something like the NCD 40-pin board that I proposed.

Cluso99

There is actually a reason for this pcb...

Many of you know my interest in Z80/CPM emulations. My P1 RamBlade is considered the smallest CPM board - it fits in a matchbox and is 1.2”x1.9”. So I need a version that is smaller to claim an unofficial prize

Cluso99

hinv wrote: »

Also, since not that many pins are brought out, would it make sense to bring more to the microSD so that QPI or better could be used?

Perhaps when someone writes the code

Would it help if I say it’s impossible

jmg

Cluso99 wrote: »

Here is a possible new P2 mini I've been working on...
* 3V3 1A LDO SOT-223
* 1V8 1A LDO SOT-223 (fed from 3V3 regulator)
Notes:
* The regulators will likely self-limit to somewhere in excess of 500mA. Switchers are not used.

Linear regulators will impose a MHz limit on P2.

The Switching ones are expanding in choice, and there are many BOM choices
* Cheapest switchers, adjustable need R/R/L - lowest price, but a bit more PCB area. (P2 Edge uses this choice)
* Fixed Voltage switchers, need external L, but integrate the divider.
* Integrated inductor switchers, some need R/R and some like Murata MYRGM180150B31RA have R/R/L all included.

The new MYRGM180150B31RA is 1.5A capable, and is 2.5mm×3.2mm, h=1.0mm
It may be possible to have a footprint choice for such a simple one-part switcher alternative ?

rogloh

If you are chasing after the smallest possible board, you might be shave ~5mm more if you are able to locate the SD card partially over the ground pad on the other side of the board if its two larger pads can be ground (and help transfer heat) and move the regulators to be side by side and possibly the serial header to the top edge. Perhaps the flash chip could squeeze between the regulators...? Having 4 layers may allow the required signals to route, not sure about 2 layers, but can't really tell until it's attempted.

Cluso99

There are smaller uSD sockets that I've used in the past eg my P8XBlade2 (should have called it the P1Blade but too late now). but this doesn;t really save me anything as those regulators take up quite a large space. Moving the serial connector to the top doesn't help as it fits ncely where it is. It's now using the newer CP2102 with uUSB.
4 layers doesn't really give me anything.

Anyway, it's mostly done now. I'll consider whether I make it depending on interest and my own thoughts over xmas.

Cluso99

jmg wrote: »

Cluso99 wrote: »

Here is a possible new P2 mini I've been working on...
* 3V3 1A LDO SOT-223
* 1V8 1A LDO SOT-223 (fed from 3V3 regulator)
Notes:
* The regulators will likely self-limit to somewhere in excess of 500mA. Switchers are not used.

Linear regulators will impose a MHz limit on P2.

The Switching ones are expanding in choice, and there are many BOM choices
* Cheapest switchers, adjustable need R/R/L - lowest price, but a bit more PCB area. (P2 Edge uses this choice)
* Fixed Voltage switchers, need external L, but integrate the divider.
* Integrated inductor switchers, some need R/R and some like Murata MYRGM180150B31RA have R/R/L all included.

The new MYRGM180150B31RA is 1.5A capable, and is 2.5mm×3.2mm, h=1.0mm
It may be possible to have a footprint choice for such a simple one-part switcher alternative ?

As you can probably gather, I have zero interest in switchers at this time. That may change later.

For my RetroBlade2...

At idle and downloading (115,200 baud) draws under 50mA

Running my OS at
200MHz draws 230mA
300MHz draws 265mA (not working as there are currently other things that also need adjusting)
360MHz takes 275mA (not working)
These figures will increase as my OS takes shape.

Running my Z80/CPM
200 MHz draws 220mA

hinv

How are you measuring those? Is that at the 5V input?

pik33

Cluso99, I like the basic idea, but as you know I would be more interested in something like the P2 Edge, but in a DIP format

+1 for this. DIP64, like MC68000, with a crystal, ROM, 1.8V regulator and PropPlug connector. On the pin side, +3v3,gnd,reset and up to 61 pins.

Cluso99

hinv wrote: »

How are you measuring those? Is that at the 5V input?

yes, at 5V, but excludes the USB-Serial module

Cluso99

pik33 wrote: »

Cluso99, I like the basic idea, but as you know I would be more interested in something like the P2 Edge, but in a DIP format

+1 for this. DIP64, like MC68000, with a crystal, ROM, 1.8V regulator and PropPlug connector. On the pin side, +3v3,gnd,reset and up to 61 pins.

This would be 3.4" long, so how wide to support it???

pik33

Cluso99 wrote: »

pik33 wrote: »

Cluso99, I like the basic idea, but as you know I would be more interested in something like the P2 Edge, but in a DIP format

+1 for this. DIP64, like MC68000, with a crystal, ROM, 1.8V regulator and PropPlug connector. On the pin side, +3v3,gnd,reset and up to 61 pins.

This would be 3.4" long, so how wide to support it???

The biggest problem may be the P2 chip which can be too big (16x16 mm?) to place it on such a board and provide space needed for all needed connections without using a multilayer board. Standard DIP64 chip is 0.8" wide. A board with pins underside should be something like 3.4..3.5x1.0..1.2" ... ~90x30 mm.

Cluso99

To get the pins out efficiently, the P2 needs to be rotated 45 deg. IIRC this means at least 1.0” wide. You’ll likely snap the pcb if you try to unplug it from a breadboard.

msrobots

Hi @Cluso99, can I download your OS and a CP/M sd to test it on rev A or rev B Eval? If so, where?

Still like to get COBOL-Z80 running. It fails on the ramblade CP/M.

Mike

Cluso99

msrobots wrote: »

Hi @Cluso99, can I download your OS and a CP/M sd to test it on rev A or rev B Eval? If so, where?

Still like to get COBOL-Z80 running. It fails on the ramblade CP/M.

Mike

Code is posted on the other RetroBlade2 thread, (your boards have arrived) plus links to extra P2 code.

Your RamBlade microSD will work for my P2 Z80/CPM as i use the same cpm files. I share the same microSD card between P1 and P2

Give cobol a try as my z80 is based on pullmoll’s z80 base code rather than heaters ZiCog. No promises. If it doesn’t run then i am after help to run zexall to find any problems.