@AkatoshTheGreat also it is fixable in mame via mames menus, but if you want to add other emulators, you will have issues as they expect a different device for each player. Unless you plan only using 1 player.
@iandaemon The Pi4 does let you rotate in 90 degree increments, though it is nowhere near as simple to do so as on previous generations of Pi. After a couple of days of fiddling, I have Emulation station and Retroarch rotated 90 degrees and (finally) filling the screen. I don’t have the setup menus rotated yet, though. At least on the MAME games I have checked so far, there are no obvious performance issues in doing it.
Rtype Leo shouldn’t need anything real special to run in Mame. Most of your games will run in the mame 4 all mame2003. But you’ll want to test some of your games in mame libretro 2003 plus. You have access to more cores like mame 2016. Also try Final Burn Neo. I run my games through retroarch on the pc to test them first then place them on my pi 4.
@lupin it may well be a generic thing that would affect the official retropie image also but they are not supported here because we don't know what has changed under the hood, and also do not want to encourage the distribution of illegal material under the retropie name, etc. the image maker calling it 'official' is particularly egregious...
Thanks! This gets stranger.
Originally I was using a MicroSD Adapter to read the card on a built-in SD card reader in an HP Elitebook 2540P I5 laptop running Windows 10. Today, I used a different micro SD card reader (a USB version this time "T-flash USB") - didn't even know I had one, but found it by chance when I was going through my USB drives in order to install gpartLIVE as bootable drive) on the same laptop. When I looked at the micro SD card using this USB reader, disk manager showed the 256MB partition, another space of several gigs, and a large unallocated space (albeit TOO large). I wiped out the partitions (using Diskpart I believe). Then I saw a capacity of 2TB of unallocated space (on a 128GB card!!!). I got gpart to run on my other Retropie SD Card (never actually needed the USB drive) and using the same USB reader, it too reported 2TB for total capacity. Other Linux utilites reported the same capacity. I tried a different SD card in this USB reader and that reader always shows SIZE 2TB, but it does show the correct partition sizes. Now I had the opposite issue - too much space reported. Various partitioning and formating utilities choked b/c I think they were trying to read/write beyond the actual capacity of the drive. On a whim, I put the card back in the original Micro SD card adapter and disk manager showed 116GB unallocated. I created a simple volume and it worked. I imaged the card and the Pi booted. Almost 24 hours later and I'm almost back to where I started. I thought these adapters were just devices which passed the connection through pin for pin with no 'smarts' in-between. Maybe the built-in card reader had an issue? Dunno. In any case, thanks for all of your help.