+mytek Posted May 14, 2022 Author Share Posted May 14, 2022 1 hour ago, ijor said: Ah, no, I thought it was very similar but not that identical. Unbelievable! The only difference is that ICD added the ability to reconfigure it for either an 800XL or a 1200XL via a few jumpers. Other than that it's virtually identical to what Claus created. Quote Link to comment Share on other sites More sharing options...
+mytek Posted May 14, 2022 Author Share Posted May 14, 2022 (edited) Making good progress... $16.75 for 3 bare PCBs shipped from OSH Park Corrected Schematic: RAMBO_XL-II_schema.pdf Incorporated Power Planes top (+5V) and bottom (GND), and gave credit to the original creator on the silk screen This board is virtually the same size as the ICD RAMBO XL, with all the components in relatively the same locations. Right angle headers will be used for J1 and J4, whereas J2 and J3 will be vertical headers mounted on the bottom side. I'm looking at using a double male sip pin header for where it's meant to plug into either J7 or J27 on the Atari motherboard, assuming the clearance works out the same as what was originally used by ICD. I believe either style will work. LINK I was originally considering specifying HCT chips, but in order to use those I'd have to be sure to tie all the unused inputs to either GND or +5V. When using the 74LSxxx chips this isn't necessary, and the ICD implementation left these floating (LS naturally pulls high). Since there are so few chips being added, the power savings by going to CMOS would be negligible. I have 10 pieces coming of the 256K DRAMS for a grand total of $15 including free shipping, which will give me two extra (only need 8). Edited May 14, 2022 by mytek 1 1 Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted May 14, 2022 Share Posted May 14, 2022 Even back in the 80s when the Rambo XL was being sold, everyone knew it was Claus' design. I have many user group newsletters and text files that made the rounds on BBSes that talked about RAM expansions and how to do various incarnations of them to various machines. All the hardware guys knew it was Claus' design even back then and gave credit whenever they mentioned it, and made light of the fact that the RAMBO XL was identicle. Claus literally set the first standard for banked memory expansions on the XL.. When the 130XE came out with factory extended ram, it was likely as not that they got the idea from user groups that were already doing claus's upgrade.. Of course, they did set in stone the 16k bank size as a standard, which was the second revision of Claus's design, if I remember correctly.. I can't remember if ICD actually offered the RAMBO XL before the 130XE came out, or not.. But, Claus' magazine articles predated both, for sure.. 5 Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 14, 2022 Share Posted May 14, 2022 1 hour ago, MEtalGuy66 said: But, Claus' magazine articles predated both, for sure.. It's true that I wrote and submitted the BYTE article before the XE appeared, but the lead time was so long that, by the time the issue came out, the XE had arrived and I had already revised the upgrade for 16K banks. At the bottom of the first page of the revised instructions, I explicitly asked only that the information be shared freely to encourage widespread use. ICD did acknowledge me in the Forward of their manual. I'm cool with it and can thank them for helping make it successful. 6 Quote Link to comment Share on other sites More sharing options...
+mytek Posted May 14, 2022 Author Share Posted May 14, 2022 4 hours ago, ClausB said: ICD did acknowledge me in the Forward of their manual. I'm cool with it and can thank them for helping make it successful. I just saw that - I guess I just kept skipping beyond the forward Who is Ron Boling? He was also acknowledged as a contributor. Quote Link to comment Share on other sites More sharing options...
+mytek Posted May 14, 2022 Author Share Posted May 14, 2022 I think a little bit more clarification was needed on who did what... So today I'll trace everything once again on the original ICD RAMBO XL board, and verify that we have a match. Then it'll be time to place a small sample order for testing and use in my two 1200XLs, as well as perhaps put one in one of my 800XLs. Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 14, 2022 Share Posted May 14, 2022 3 hours ago, mytek said: Who is Ron Boling? I wondered the same. Quote Link to comment Share on other sites More sharing options...
Ricky Spanish Posted May 14, 2022 Share Posted May 14, 2022 10 minutes ago, ClausB said: I wondered the same. I think he was head of the 130XE team. 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted May 14, 2022 Author Share Posted May 14, 2022 (edited) Today I did something I had been resistant to do, and that was stripping all the components from my one and only original ICD RAMBO XL PCB so that I could really see all the trace connections more clearly. ICD used very tiny pads, so I did have a couple lift unfortunately, Well I guess it's a good thing I'm designing a replacement After doing this I could see that all unused inputs were indeed not left floating, and instead are pulled high (+5V). I also saw two places for decoupling capacitors to go (I marked these with yellow rectangles), However my board never had these installed. The cap down by where the RAMBO would plug into either U7 or U27 was redundant considering that the chip socket on the Atari motherboard already has its own decoupling cap, however the one shown between IC4 and IC5 is a good precaution. So I updated my schematic as well as the clone PCB to pull-up the unused inputs and to include one decoupling capacitor. We are now at Version 1.1 for the board with these changes. So I guess now it would be permissible to substitute SN74HCTxxx parts for the 74LSxxx ones, since all inputs now go somewhere (I should have done this right from the get go). Updated schematic: RAMBO_XL-II_V1.1_schema.pdf I'm now ready to order a few sample boards ? Edited May 14, 2022 by mytek 8 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted May 15, 2022 Share Posted May 15, 2022 9 hours ago, ClausB said: I wondered the same. Quote RD.COM supports the standard 130XE, the 130XE with 64K RAM upgrade (from Ron Boling), and the new 256K RAMBO XL upgrade for the 800XL and 1200XL computers. Hmmmm. 192k 130XE upgrade? Quote Link to comment Share on other sites More sharing options...
+mytek Posted June 9, 2022 Author Share Posted June 9, 2022 RAMBO XL-II Ready for Production Assembled Board TOP (I used HCT chips, but the original 74LS chips can be used as well) Assembled Board BOTTOM Installed in 1200XL with Sophia Rev C Buy Bare PCB from OSH Park (minimum order of 3 pieces for $16.75, which includes free international shipping) Buy LINK Schematic: RAMBO_XL-II_V1.1_schema.pdf Gerbers: RAMBO_XL-II_gerbers.zip Manual: RamboXLManual.pdf Sorry no BOM, but between the PCB silkscreen and the schematic it should be pretty easy to figure out what is needed. Here's a LINK to the double pin header strip used for piggybacking. 10 Quote Link to comment Share on other sites More sharing options...
+mytek Posted June 10, 2022 Author Share Posted June 10, 2022 (edited) Too late to add this to my previous post... If you upload the zipped Gerber file to JLCPCB, then pick their cheapest shipping option (takes about 2-1/2 weeks), you can get 5-10 boards for half the price of what OSH Park charges for 3. As an example, I ordered 10 sample boards from JLCPCB and the grand total with shipping was $9.40 (less than $1 a piece). Pretty good deal, only requiring a tiny bit more work on your part during the ordering process Edited June 10, 2022 by mytek 3 Quote Link to comment Share on other sites More sharing options...
+selgus Posted June 10, 2022 Share Posted June 10, 2022 10 hours ago, mytek said: Too late to add this to my previous post... If you upload the zipped Gerber file to JLCPCB, then pick their cheapest shipping option (takes about 2-1/2 weeks), you can get 5-10 boards for half the price of what OSH Park charges for 3. As an example, I ordered 10 sample boards from JLCPCB and the grand total with shipping was $9.40 (less than $1 a piece). Pretty good deal, only requiring a tiny bit more work on your part during the ordering process I use JLCPCB all the time and have had great results. I tend to panelize my designs and then get 10 copies of the panels, for a great price. Only thing to remember is these are being shipped from China and shipping charges do add up. 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted June 10, 2022 Author Share Posted June 10, 2022 7 hours ago, selgus said: I use JLCPCB all the time and have had great results. I know a lot of people like to use PCBWAY, but I just ran a quote on this same board at their minimum order of 5 pieces using their cheapest shipping option, and it came to a similar price as OSH Park for 3 pieces. Still a better deal then OSH Park because you get an extra 2 boards, but more expensive by about $5 as compared to JLCPCB for the same 5 boards. In all 3 cases using the cheapest shipping option ends up getting the boards to you in approximately 2 weeks. The RAMBO XL-II board is a standard 2-layer 1.6mm thick (40mm x 54mm) PCB. On the other hand when it comes to the 4-layer boards I use in some of my designs, these tend to be wayyyyyy more expensive via PCBWAY, and out of this world at OSH Park, with JLCPCB being hands down the best choice for multi-layer boards. JLC for the win ? 7 hours ago, selgus said: I tend to panelize my designs and then get 10 copies of the panels, for a great price. Only thing to remember is these are being shipped from China and shipping charges do add up. Do they charge extra for panelizing? 1 Quote Link to comment Share on other sites More sharing options...
+selgus Posted June 10, 2022 Share Posted June 10, 2022 43 minutes ago, mytek said: Do they charge extra for panelizing? It depends, but what I've found by experimenting is better pricing doing a panel instead of just having that same quantity of individual boards. Plus when I build up some of my designs, I will do build a panel at a time. Most of my designs are 4-layer boards these days, and I've found that JLCPCB has been the best value. 1 Quote Link to comment Share on other sites More sharing options...
Mathy Posted June 10, 2022 Share Posted June 10, 2022 Hello guys All these PCB making companies are located in China? Sincerely Mathy Quote Link to comment Share on other sites More sharing options...
kenames99 Posted June 11, 2022 Share Posted June 11, 2022 1 hour ago, Mathy said: Hello guys All these PCB making companies are located in China? Sincerely Mathy hi Mathy, Yes, jlc and pcbway are both in China. Ken Quote Link to comment Share on other sites More sharing options...
Mathy Posted June 11, 2022 Share Posted June 11, 2022 (edited) Hello Ken 10 hours ago, kenames99 said: Yes, jlc and pcbway are both in China. And OSH Park? Sincerely Mathy Edited June 11, 2022 by Mathy Quote Link to comment Share on other sites More sharing options...
reifsnyderb Posted June 11, 2022 Share Posted June 11, 2022 1 hour ago, Mathy said: Hello Ken And OSH Park? Sincerely Mathy OSH Park are in the USA. I think Oregon. 1 Quote Link to comment Share on other sites More sharing options...
Ricky Spanish Posted June 11, 2022 Share Posted June 11, 2022 On 5/12/2022 at 3:21 PM, mytek said: So my plan is to make up a small batch of RAMBO XL clone boards that uses a right angle header for all the wire connections. Sign me up for one. Quote Link to comment Share on other sites More sharing options...
+mytek Posted June 11, 2022 Author Share Posted June 11, 2022 4 hours ago, Ricky Spanish said: Sign me up for one. Nothing to sign up for, because I don't sell anything myself. I simply create, clone, and/or embellish existing designs and put them into the public domain for others to use. Sometimes someone such as @MacRorie will choose to manufacture and sell a version.. 1 1 Quote Link to comment Share on other sites More sharing options...
Ricky Spanish Posted June 11, 2022 Share Posted June 11, 2022 5 hours ago, mytek said: Nothing to sign up for, because I don't sell anything myself Ahhhh gotcha. Reading through your posts, could you provide links for all parts purchased ? I wouldn't mind taking a shot at building one. Thanks. Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted June 12, 2022 Share Posted June 12, 2022 On 6/10/2022 at 2:27 PM, mytek said: I know a lot of people like to use PCBWAY, but I just ran a quote on this same board at their minimum order of 5 pieces using their cheapest shipping option, and it came to a similar price as OSH Park for 3 pieces. Still a better deal then OSH Park because you get an extra 2 boards, but more expensive by about $5 as compared to JLCPCB for the same 5 boards. In all 3 cases using the cheapest shipping option ends up getting the boards to you in approximately 2 weeks. The RAMBO XL-II board is a standard 2-layer 1.6mm thick (40mm x 54mm) PCB. On the other hand when it comes to the 4-layer boards I use in some of my designs, these tend to be wayyyyyy more expensive via PCBWAY, and out of this world at OSH Park, with JLCPCB being hands down the best choice for multi-layer boards. JLC for the win ? Do they charge extra for panelizing? I like using them too. I had ordered some small boards a while back and they did a great job. I had just recently placed an order for some replacement keyboards PCB's and connectors the price and options was pretty good. I had to pay a more for another carrier since I the post office has not been too reliable with some deliveries to me. 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted June 12, 2022 Author Share Posted June 12, 2022 2 hours ago, Ricky Spanish said: Ahhhh gotcha. Reading through your posts, could you provide links for all parts purchased ? I wouldn't mind taking a shot at building one. Thanks. Sorry but presently what I've uploaded is all you get at the moment from me. Maybe in the future if I opt to put this on my website I'll take the time to create a proper BOM. Quote Link to comment Share on other sites More sharing options...
ClausB Posted June 12, 2022 Share Posted June 12, 2022 The original article linked upthread has a BOM. Just add some jumper headers. 1 2 Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.